AP Computer Science Principles Unit 3: Big Idea 3: Algorithms and Programming Practice Exam

Assessment for Unit 3: Big Idea 3: Algorithms and Programming

Estimated Time: 90 minutes

Exam Details

Questions: 90 total (90 multiple choice)
Time: 90 minutes (recommended)
Topics Covered: Unit 3: Big Idea 3: Algorithms and Programming
Format: Multiple Choice questions matching real exam difficulty
Scoring: Instant results with detailed explanations

A. Multiple-Choice Questions (90 Questions)

Select the one best answer for each question.

1. Consider the following code segment: ``` score <- 50 score <- score + 10 score <- score * 2 ``` What is the value of score after this code segment is executed?

(A)50(B)60(C)110(D)120

2. A programmer is creating a game and needs to store the player's remaining lives, which is a whole number. Which of the following is the most appropriate and meaningful variable name to use?

(A)L(B)x(C)player_lives(D)isAlive

3. Consider the following code segment: ``` a <- 10 b <- 20 a <- b ``` What are the final values of variables a and b?

(A)a is 10, b is 10(B)a is 10, b is 20(C)a is 20, b is 10(D)a is 20, b is 20

4. In programming, a variable is best described as an abstraction for which of the following?

(A)A sequence of instructions(B)A location in the computer's memory(C)A true or false condition(D)A collection of related data items

5. A program is intended to calculate the total cost of an item including tax. The price of the item is stored in a variable price, and the tax rate is stored in taxRate. Which of the following code segments correctly calculates and stores the final cost in a variable totalCost?

(A)price + price * taxRate <- totalCost(B)(C)totalCost = price + taxRate(D)

6. A program needs to store the names of all 50 states in the United States. Which of the following data abstractions is the most effective way to store this information?

(A)Fifty separate string variables, one for each state.(B)A single list variable containing 50 string elements.(C)A single integer variable representing the count of states.(D)A single Boolean variable.

7. Consider the following list, where the first element is at index 1. ``` colors <- ["red", "green", "blue", "yellow"] ``` Which of the following expressions correctly accesses the element "blue"?

(A)colors[2](B)colors[3](C)(D)colors[blue]

8. How does the use of a list to store a collection of related data, such as student grades, help manage complexity in a program?

(A)It guarantees that the program will run faster.(B)It allows a group of data to be referenced by a single name, simplifying operations on the group.(C)It eliminates the need for loops when processing the data.(D)It converts all data into a numerical format for easier calculation.

9. Which of the following statements best describes the concept of data abstraction?

(A)The process of converting data from one type to another, such as from a number to a string.(B)The process of hiding the complex details of data storage and representation to focus on its essential features.(C)The process of ensuring that all variables in a program have unique names.(D)The process of executing program statements in a specific, sequential order.

10. A programmer creates a list to store a player's inventory in a game. The list is defined as follows: ``` inventory <- ["sword", "shield", 15, "potion"] ``` Which of the following statements about the inventory list is true?

(A)The list is invalid because it contains both strings and a number.(B)The list contains four elements, where the element at index 3 is the number 15.(C)The element "sword" is at index 0.(D)The length of the list cannot be determined because it contains mixed data types.

11. What is the result of the expression 10 + 4 * 2?

(A)16(B)18(C)28(D)20

12. What is the result of the expression 17 MOD 5?

(A)1(B)2(C)3(D)3.4

13. Consider the following code segment: ``` x <- 3 y <- 5 z <- (x + y) / 2 ``` What is the value of z after this code segment executes?

(A)3(B)4(C)5.5(D)8

14. Which of the following concepts ensures that each step of an algorithm is executed in the order it is written?

(A)Selection(B)Iteration(C)Abstraction(D)Sequencing

15. A programmer wants to calculate the average of three exam scores stored in variables score1, score2, and score3. Which expression correctly calculates the average?

(A)score1 + score2 + score3 / 3(B)(C)score1 / 3 + score2 + score3(D)

16. Consider the following code segment: ``` firstName <- "Ada" lastName <- "Lovelace" fullName <- firstName + " " + lastName ``` What is the value of fullName after this code is executed?

(A)"AdaLovelace"(B)"Ada Lovelace"(C)"Ada" " " "Lovelace"(D)The code will result in an error.

17. The joining of two strings, end-to-end, is known as which of the following?

(A)Substring(B)Concatenation(C)Abstraction(D)Assignment

18. If the variable word contains the string "COMPUTER", which of the following expressions would result in the substring "PUT"?

(A)SUBSTRING(word, 3, 5)(B)(C)(D)

19. Consider the following code segment: ``` val1 <- "10" val2 <- "20" result <- val1 + val2 ``` What is the value of result?

(A)30(B)"30"(C)"1020"(D)The code will cause an error because you cannot add strings.

20. A program needs to display a message Hello, <name>! where <name> is the value stored in the variable userName. Which of the following expressions correctly creates this message?

(A)"Hello, " + userName + "!"(B)"Hello, " + "<name>" + "!"(C)"Hello, userName!"(D)"Hello," + " " + userName

21. The variable age holds the value 18. Which of the following Boolean expressions evaluates to true?

(A)age < 18(B)age > 18(C)age = 18(D)age ≠ 18

22. Consider the expression (x > 5) AND (x < 10). For which of the following values of x will the expression evaluate to true?

(A)5(B)7(C)10(D)12

23. The variable isRaining is false and the variable isSunny is true. What is the result of the expression NOT isRaining AND isSunny?

(A)true(B)false(C)0(D)The expression is invalid.

24. Which of the following expressions is equivalent to NOT (a = b)?

(A)a > b(B)a < b(C)a ≠ b(D)a AND b

25. A theme park ride has the following requirements: a person must be at least 54 inches tall OR have an adult with them. Let height be the person's height and withAdult be a Boolean variable. Which expression is true if the person is allowed on the ride?

(A)(height ≥ 54) AND (withAdult = true)(B)(C)(D)

26. Consider the following code segment: ``` temperature <- 85 ``` IF (temperature > 80) ``` { DISPLAY("It's a hot day!") } ``` ELSE ``` { DISPLAY("It's a pleasant day.") } ``` What is displayed when this code is executed?

(A)It's a hot day!(B)It's a pleasant day.(C)Both messages are displayed.(D)Nothing is displayed.

27. The use of an IF statement in an algorithm to execute different code based on a condition is an example of which programming construct?

(A)Sequencing(B)Iteration(C)Selection(D)Abstraction

28. Consider the following code segment, where score is 95. IF (score > 90) ``` { DISPLAY("A") } ``` IF (score > 80) ``` { DISPLAY("B") } ``` What is displayed when this code is executed?

(A)A(B)B(C)AB(D)Nothing is displayed.

29. Consider the following code segment: ``` x <- 10 y <- 10 ``` IF (x = y) ``` { x <- x + 5 } ``` ELSE ``` { y <- y + 5 } ``` What are the final values of x and y?

(A)x is 10, y is 10(B)x is 15, y is 10(C)x is 10, y is 15(D)x is 15, y is 15

30. An algorithm needs to check if a number is positive. The number is stored in the variable num. Which code segment correctly displays "Positive" only if num is greater than 0?

(A)IF (num > 0) { DISPLAY("Positive") }(B)(C)(D)

31. Consider the following code segment, where age is 20 and hasLicense is true. IF (age >= 16) ``` { ``` IF (hasLicense) ``` { DISPLAY("Can drive") } ``` ELSE ``` { DISPLAY("Cannot drive yet") } } ``` ELSE ``` { DISPLAY("Too young to drive") } ``` What is the output of this code?

(A)Can drive(B)Cannot drive yet(C)Too young to drive(D)No output is produced.

32. Consider the following code segment, where score is 85. ``` grade <- "F" ``` IF (score >= 60) ``` { grade <- "D" ``` IF (score >= 70) ``` { grade <- "C" ``` IF (score >= 80) ``` { grade <- "B" ``` IF (score >= 90) ``` { grade <- "A" } } } } DISPLAY(grade) ``` What is displayed when this code runs?

(A)A(B)B(C)C(D)D

33. Which of the following logical expressions is equivalent to the nested conditional structure shown below? IF (isWeekend) ``` { ``` IF (isSunny) ``` { DISPLAY("Go to the park.") } } ```

(A)IF (isWeekend OR isSunny)(B)(C)(D)

34. Consider the following code segment where temp is 30. IF (temp <= 32) ``` { DISPLAY("Freezing") } ``` ELSE ``` { ``` IF (temp >= 100) ``` { DISPLAY("Boiling") } ``` ELSE ``` { DISPLAY("Liquid") } } ``` What is the output?

(A)Freezing(B)Boiling(C)Liquid(D)Both Freezing and Liquid are displayed.

35. A programmer is writing code to determine a shipping cost. If an order total is over 100 dollars, shipping is free. If the order is 100 dollars or less, shipping is 5 dollars for standard shipping and 15 dollars for express shipping. Which of the following best describes the control structure needed?

(A)A single IF statement.(B)A sequence of three independent IF statements.(C)An IF-ELSE statement with another IF-ELSE statement nested inside the ELSE block.(D)A loop that repeats until the shipping cost is determined.

36. Consider the following code segment: ``` count <- 0 REPEAT 5 TIMES { count <- count + 1 } DISPLAY(count) ``` What is the final value displayed?

(A)0(B)1(C)4(D)5

37. Consider the following code segment: ``` x <- 10 REPEAT UNTIL (x = 5) { DISPLAY(x) x <- x - 1 } ``` Which of the following best describes the output of this code?

(A)The numbers 10, 9, 8, 7, 6, 5 are displayed.(B)The numbers 10, 9, 8, 7, 6 are displayed.(C)The number 5 is displayed.(D)The code results in an infinite loop.

38. A program needs to process every item in a list of 100 student names. Which control structure is most appropriate for this task?

39. ``` What happens in a REPEAT UNTIL (condition) loop if the condition is true the very first time it is checked? ```

(A)The loop body executes exactly once.(B)The loop body is not executed at all.(C)The program produces an error.(D)The loop becomes an infinite loop.

40. Consider the following code segment: ``` num <- 1 REPEAT UNTIL (num > 10) { num <- num + 2 } DISPLAY(num) ``` What value is displayed?

(A)9(B)10(C)11(D)12

41. Consider the following two algorithms, which are intended to calculate the sum of the integers from 1 to 4. Algorithm A ``` sum <- 1 + 2 + 3 + 4 DISPLAY(sum) ``` Algorithm B ``` sum <- 0 count <- 1 REPEAT UNTIL (count > 4) { sum <- sum + count count <- count + 1 } DISPLAY(sum) ``` Which of the following statements is true?

(A)Only Algorithm A produces the correct result.(B)Only Algorithm B produces the correct result.(C)Both algorithms produce the correct result.(D)Neither algorithm produces the correct result.

42. A programmer has already created a correct algorithm findMax(list) that returns the largest value in a list of numbers. The programmer now needs to find the largest value in the first half of a list called myList. Which of the following represents the best approach?

(A)Rewrite the findMax algorithm from scratch to only work on half a list.(B)Create a new list containing only the first half of myList, then use the existing findMax algorithm on the new list.(C)Test every number in myList to see if it is in the first half before comparing it.(D)It is not possible to reuse the existing algorithm.

43. Which of the following is NOT a benefit of using existing, correct algorithms as building blocks for creating new algorithms?

(A)It reduces program development time.(B)It guarantees the new algorithm will be more efficient than any other possible solution.(C)It simplifies the process of testing and debugging the new program.(D)It makes the program's logic easier to understand by breaking it into smaller parts.

44. A developer wants to create an algorithm to find the average of a list of numbers. A known, correct algorithm for finding the sum of a list is available. Which of the following describes how the developer could create the new algorithm?

(A)Use the summing algorithm, then divide the result by the length of the list.(B)Use the summing algorithm, then multiply the result by the length of the list.(C)The summing algorithm cannot be used to help find the average.(D)Create a loop that divides each number by the length of the list.

45. Consider the following code segment: IF (score > 70) ``` { passed <- true } ``` ELSE ``` { passed <- false } ``` Which of the following single lines of code is equivalent to the segment above?

(A)passed <- score < 70(B)passed <- score >= 70(C)passed <- score > 70(D)passed <- score = 70

46. ``` Consider the list nums <- [10, 20, 30, 40]. The following code is executed. sum <- 0 ``` FOR EACH item IN nums ``` { sum <- sum + item } DISPLAY(sum) ``` What is the output?

(A)10(B)40(C)100(D)An error occurs.

47. ``` The list letters <- ["a", "b", "c", "d"] is modified by the command INSERT(letters, 3, "x"). What is the state of the list letters after the command executes? ```

(A)["a", "b", "x", "c", "d"](B)["a", "b", "c", "x", "d"](C)["a", "b", "x"](D)["a", "b", "c", "d", "x"]

48. The following algorithm is intended to find the minimum value in a list of positive numbers called data. ``` minVal <- 0 ``` FOR EACH num IN data ``` { ``` IF (num < minVal) ``` { minVal <- num } } RETURN minVal ``` Which of the following best describes the behavior of this algorithm?

(A)It correctly finds the minimum value for any list of positive numbers.(B)It will always return 0, regardless of the list's contents.(C)It correctly finds the maximum value, not the minimum.(D)It will cause an error because minVal is not in the list.

49. The process of accessing each element of a list, one at a time, is known as what?

(A)Indexing(B)Assignment(C)Traversal(D)Concatenation

50. A list items contains 5 elements. What happens if a program attempts to access items[6]?

(A)The program accesses the first element of the list.(B)The program returns a value of 0.(C)The program terminates because the index is out of bounds.(D)The program adds a new element at index 6.

51. What is the most important prerequisite for a list to be searched using a binary search algorithm?

(A)The list must contain only numbers.(B)The list must not contain any duplicate values.(C)The list must be sorted.(D)The list must have an even number of elements.

52. Consider the sorted list [2, 8, 11, 15, 22, 29, 34, 40]. A binary search is performed to find the value 29. What is the first value in the list that will be checked?

(A)2(B)15(C)22(D)40

53. Which of the following best explains why binary search is generally more efficient than linear search for finding an element in a large list?

(A)Binary search checks every element, while linear search only checks some elements.(B)Binary search requires less memory to store the list.(C)Binary search eliminates half of the remaining data set with each comparison.(D)Binary search works on unsorted lists, which saves time.

54. A sorted list contains 1,000 elements. In the worst-case scenario, approximately how many comparisons will a binary search take to find a value or determine it is not in the list?

(A)10(B)500(C)1000(D)2000

55. A linear search algorithm is used to find a value in a list of n items. In the worst-case scenario, how many elements of the list must be checked?

(A)1(B)n / 2(C)n(D)n * 2

56. Consider the following procedure definition: ``` PROCEDURE calculateArea(length, width) { RETURN(length * width) } ``` Which of the following is a valid call to this procedure?

(A)calculateArea()(B)(C)(D)

57. In the context of procedures, what is the difference between a parameter and an argument?

(A)There is no difference; the terms are interchangeable.(B)A parameter is the value passed to a procedure, while an argument is the variable in the procedure definition that receives the value.(C)A parameter is the variable in the procedure definition, while an argument is the actual value passed to the procedure when it is called.(D)A parameter is used in procedures that return values, while an argument is used in procedures that do not.

58. Consider the following code segment: ``` PROCEDURE updateScore(currentScore) { currentScore <- currentScore + 100 RETURN(currentScore) } score <- 50 newScore <- updateScore(score) DISPLAY(score) ``` What value is displayed by this program?

(A)50(B)100(C)150(D)An error occurs because score is modified.

59. ``` What is the primary function of a RETURN statement in a procedure? ```

(A)To display a value to the user.(B)To stop the entire program's execution.(C)To pass a value back to the part of the program that called the procedure.(D)To declare a new variable inside the procedure.

60. A program uses a procedure GET_INPUT() which waits for the user to type something and press Enter, then returns what the user typed. Which line of code correctly stores the user's input in a variable named userName?

(A)GET_INPUT(userName)(B)(C)(D)

61. Which of the following best describes how procedural abstraction helps manage program complexity?

(A)It ensures that the program runs as fast as possible by optimizing low-level code.(B)It allows programmers to use a procedure without needing to know the details of how it is implemented.(C)It requires all code to be written in a single, large block, which is easier to read sequentially.(D)It automatically converts complex data types into simpler ones.

62. A programmer needs to create a procedure that calculates the sales tax for a given price. The procedure should take the price and the tax rate as inputs and return the calculated tax amount. Which of the following procedure definitions is the most appropriate?

(A)PROCEDURE calculateTax() { price <- 100; rate <- 0.05; RETURN(price * rate) }(B)(C)(D)

63. The process of breaking a large computer program into smaller, independent subprograms (procedures) is known as what?

(A)Sequencing(B)Iteration(C)Modularity(D)Efficiency

64. A team of programmers is working on a large project. They decide to use procedural abstraction to divide the work. How does this approach help their collaboration?

(A)It forces all programmers to use the exact same variable names.(B)It eliminates the need for any communication between team members.(C)It ensures that the final program will have no bugs.(D)It allows different programmers to work on separate procedures independently, as long as they agree on what each procedure does.

65. A programmer writes a procedure findAverage(numList) to calculate the average of numbers in a list. Later, the programmer finds a more efficient way to calculate the sum inside the procedure. How does procedural abstraction benefit the programmer in this situation?

(A)The programmer must rewrite all parts of the program that call findAverage.(B)The programmer can update the internal logic of findAverage without changing the parts of the program that call it.(C)The programmer must change the name of the procedure to findAverageV2.(D)The programmer cannot change the procedure once it has been written.

66. What is the primary purpose of a software library?

(A)To provide a collection of pre-written, reusable procedures to simplify program development.(B)To store documentation and comments about a program.(C)To translate program code from a high-level language to machine code.(D)To provide a graphical user interface for interacting with a program.

67. A developer is building an application that needs to perform complex mathematical calculations. Instead of writing the code for these calculations from scratch, the developer decides to use a pre-existing math library. This is an example of what concept?

(A)Developing an algorithm from scratch.(B)Simplifying a program by removing features.(C)Using abstraction to manage complexity.(D)Creating an undecidable problem.

68. What is an Application Program Interface (API)?

(A)The hardware that a program runs on.(B)A set of definitions and protocols for how to use the procedures in a software library.(C)A programming language used for creating web applications.(D)A tool for debugging and finding errors in code.

69. A programmer wants to use a procedure from a graphics library to draw a circle. The procedure call is drawCircle(x, y, radius, color). To understand what values to provide for x, y, radius, and color, what should the programmer consult?

(A)The computer's hardware manual.(B)The library's documentation or API.(C)The source code of the operating system.(D)A list of all variables in their own program.

70. Which of the following is a significant benefit of using libraries in programming?

(A)It guarantees that the program is unique and no other program functions similarly.(B)It allows developers to build upon the reliable work of others, saving time and reducing errors.(C)It decreases the final size of the program file.(D)It makes the program run on any type of computer without modification.

71. A program uses the procedure RANDOM(a, b), which generates a random integer from a to b, inclusive. Which expression generates a random integer representing the roll of a standard six-sided die?

(A)RANDOM(0, 5)(B)(C)(D)

72. ``` A program executes the statement result <- RANDOM(1, 10). Which of the following values could result NOT possibly have? ```

(A)1(B)5(C)10(D)11

73. ``` A programmer wants to simulate flipping a coin. The outcome should be either "Heads" or "Tails". They generate a random number like this: flip <- RANDOM(0, 1). Which of the following code segments correctly uses this random number to assign the outcome? ```

74. What is the primary effect of using random number generation in a program?

(A)It makes the program run significantly faster.(B)It ensures the program always produces the exact same output.(C)It can cause the program to produce a different result each time it is executed.(D)It reduces the amount of memory the program requires.

75. Which expression generates a random even integer between 2 and 10, inclusive (i.e., 2, 4, 6, 8, or 10)?

(A)RANDOM(2, 10)(B)(C)(D)

76. A computer program that models the movement of planets in the solar system is an example of what?

(A)An undecidable problem(B)A simulation(C)A software library(D)A heuristic

77. When creating a computer simulation of a real-world phenomenon, developers often remove or simplify complex details. This process is a form of what?

(A)Iteration(B)Sequencing(C)Abstraction(D)Debugging

78. Which of the following is a primary benefit of using computer simulations?

(A)They provide results that are always 100% accurate representations of the real world.(B)They allow for the study of phenomena that are too dangerous, expensive, or slow to observe in reality.(C)They can solve problems for which no algorithm can be created.(D)They eliminate all potential for bias in scientific research.

79. A simulation is created to model traffic flow in a city. The creators of the simulation only include data for cars and do not include data for buses, bicycles, or pedestrians. This omission could lead to what issue?

(A)The simulation will run faster than expected.(B)The simulation will be more accurate than the real world.(C)The simulation may contain bias and produce inaccurate predictions.(D)The simulation will require more computing power to run.

80. How can random numbers be useful in a simulation of a customer service call center?

(A)To ensure every customer has the exact same wait time.(B)To model the unpredictable arrival times of calls from customers.(C)To guarantee that the simulation's output is the same every time it runs.(D)To sort the list of employee names alphabetically.

81. An algorithm's efficiency is typically measured in terms of its use of which two computational resources?

(A)Programming language and operating system(B)(C)User interface and network speed(D)Input and output

82. An algorithm has a running time that is proportional to n^2, where n is the size of the input. Another algorithm for the same problem has a running time proportional to 2^n. Which of the following statements is true for large values of n?

(A)The n^2 algorithm is considered to run in a reasonable amount of time, while the 2^n algorithm is not.(B)The 2^n algorithm is considered to run in a reasonable amount of time, while the n^2 algorithm is not.(C)Both algorithms are considered to run in a reasonable amount of time.(D)Neither algorithm is considered to run in a reasonable amount of time.

83. The "Traveling Salesperson Problem" asks for the shortest possible route that visits a set of cities and returns to the origin city. For a large number of cities, no efficient algorithm is known to find the absolute best solution. In such cases, programmers often use an approach that provides a "good enough" solution, even if it might not be the absolute best. What is this type of approach called?

(A)A decidable problem(B)An undecidable problem(C)A heuristic(D)A simulation

84. Algorithm X performs a search on a list of n items. Its efficiency can be described as linear. Algorithm Y performs the same search, and its efficiency is constant. Which algorithm is more efficient for a very large list?

(A)Algorithm X(B)Algorithm Y(C)Both are equally efficient.(D)It is impossible to determine without knowing the exact number of items.

85. Which of the following is an example of an algorithm that runs in an unreasonable amount of time?

(A)An algorithm with linear efficiency.(B)An algorithm with polynomial efficiency.(C)An algorithm with exponential efficiency.(D)An algorithm with constant efficiency.

86. Which of the following best defines an undecidable problem?

(A)A problem that takes a very long time for a computer to solve.(B)A problem for which no algorithm can ever be created that will always provide a correct yes-or-no answer for all inputs.(C)A problem that has not yet been solved, but for which an algorithm is expected to be found in the future.(D)A problem that can only be solved using a heuristic approach.

87. Which of the following is a decidable problem?

(A)Determining if a given integer is even or odd.(B)(C)Determining if a program is free of all possible bugs.(D)Determining if two programs will produce the exact same output for all possible inputs.

88. What is the significance of the existence of undecidable problems in computer science?

(A)It shows that modern computers are not yet fast enough.(B)It proves that all problems can eventually be solved with better algorithms.(C)It demonstrates that there are fundamental limits to what can be computed, regardless of processing power or time.(D)It suggests that quantum computing will be able to solve all problems.

89. A decision problem is a problem that can be answered with what kind of output?

(A)A number(B)A list of values(C)(D)A string of text

90. Consider the following statement: "For an undecidable problem, it is impossible to find a solution for any specific instance of the problem." Is this statement accurate?

(A)Yes, no algorithm can solve any part of an undecidable problem.(B)No, an algorithm might exist for some specific instances of the problem, but no single algorithm can solve all instances.(C)Yes, because undecidable problems are purely theoretical and have no specific instances.(D)No, because a faster computer can solve all instances of any undecidable problem.

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