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AP Computer Science Principles Practice Quiz: Parallel and Distributed Computing

Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026

Test your understanding with short quizzes. This quiz has 16 questions to check your progress.

Question 1 of 16

Which computational model is described as performing operations in order, one at a time?

All Questions (16)

Which computational model is described as performing operations in order, one at a time?

A) Parallel computing

B) Distributed computing

C) Sequential computing

D) Simultaneous computing

Correct Answer: C

According to the provided text, 'Sequential computing is a computational model in which operations are performed in order one at a time.'

A program is broken into multiple smaller operations, some of which are performed simultaneously. This is an example of which computational model?

A) Sequential computing

B) Parallel computing

C) Distributed computing

D) Ordered computing

Correct Answer: B

The text states, 'Parallel computing is a computational model where the program is broken into multiple smaller sequential computing operations, some of which are performed simultaneously.'

A task consists of four steps that must be performed sequentially. The steps take 5, 10, 8, and 12 seconds, respectively. How long will the entire task take to complete?

A) 12 seconds

B) 23 seconds

C) 35 seconds

D) It cannot be determined from the information given.

Correct Answer: C

The text explains that 'A sequential solution takes as long as the sum of all of its steps.' Therefore, the total time is 5 + 10 + 8 + 12 = 35 seconds.

A computing solution involves a 10-second sequential task, followed by three parallel tasks that take 15, 25, and 20 seconds respectively. What is the total time required to complete the solution?

A) 35 seconds

B) 60 seconds

C) 70 seconds

D) 25 seconds

Correct Answer: A

The provided content states, 'A parallel computing solution takes as long as its sequential tasks plus the longest of its parallel tasks.' The total time is the sum of the sequential part (10 seconds) and the longest parallel part (25 seconds), which equals 10 + 25 = 35 seconds.

How is the 'speedup' of a parallel solution calculated?

A) The time it took in parallel divided by the sequential time.

B) The sequential time minus the parallel time.

C) The sequential time divided by the time it took in parallel.

D) The number of parallel tasks multiplied by the time for the longest task.

Correct Answer: C

The text defines speedup as 'the time it took to complete the task sequentially divided by the time it took to complete the task when done in parallel.'

A problem takes 120 seconds to solve using a sequential approach. A parallel solution solves the same problem in 30 seconds. What is the speedup of the parallel solution?

A) 4

B) 90

C) 0.25

D) 150

Correct Answer: A

Speedup is calculated by dividing the sequential time by the parallel time. In this case, 120 seconds / 30 seconds = 4.

What is the primary factor that limits the efficiency of a parallel computing solution, even when more parallel portions are added?

A) The number of devices used

B) The speed of the fastest parallel task

C) The sequential portion of the solution

D) The total storage needs

Correct Answer: C

The text states, 'When increasing the use of parallel computing in a solution, the efficiency of the solution is still limited by the sequential portion.'

Which computational model is specifically identified as using multiple devices to run a program?

A) Sequential computing

B) Parallel computing

C) Simultaneous computing

D) Distributed computing

Correct Answer: D

The definition provided is, 'Distributed computing is a computational model in which multiple devices are used to run a program.'

A climate modeling problem is too large to fit into the memory of a single supercomputer. Which computational model would be most appropriate for solving this problem?

A) Sequential computing, because it is simpler to implement.

B) Parallel computing, because it can break the problem into smaller pieces.

C) Distributed computing, because it can use the storage of multiple devices.

D) A hybrid model that is not described in the text.

Correct Answer: C

The text explains that 'Distributed computing allows problems to be solved that could not be solved on a single computer because of either the processing time or storage needs involved.' The storage need is the key factor here.

According to the provided text, what is a key benefit of solutions that use parallel computing over those that use sequential computing?

A) They always require less storage.

B) They can scale more effectively.

C) They are always faster, regardless of the task.

D) They do not have a sequential portion.

Correct Answer: B

The text explicitly states, 'Solutions that use parallel computing can scale more effectively than solutions that use sequential computing.'

What is the fundamental method suggested by the text for comparing the efficiency of different problem solutions?

A) Comparing the number of steps in each solution.

B) Comparing the time it takes them to perform the same task.

C) Comparing the number of processors used.

D) Comparing the complexity of their algorithms.

Correct Answer: B

The text states, 'Comparing efficiency of solutions can be done by comparing the time it takes them to perform the same task.'

A developer notices that after a certain point, adding more processors to their parallel program does not result in a meaningful decrease in completion time. This phenomenon is best explained by which concept?

A) The speedup of the solution has reached its maximum.

B) The efficiency is limited by the sequential portion of the program.

C) The problem is better suited for distributed computing.

D) The individual processors are running too slowly.

Correct Answer: B

This scenario is described in the text: '...the efficiency of the solution is still limited by the sequential portion. This means that at some point, adding parallel portions will no longer meaningfully increase efficiency.'

What are the two distinct portions that make up a parallel computing solution?

A) An input portion and an output portion

B) A distributed portion and a local portion

C) A parallel portion and a sequential portion

D) A primary portion and a secondary portion

Correct Answer: C

The text mentions that 'Parallel computing consists of a parallel portion and a sequential portion.'

Which statement best describes a key difference between parallel and distributed computing based on the provided text?

A) Parallel computing performs operations simultaneously, while distributed computing performs them sequentially.

B) Parallel computing breaks a program into smaller operations, while distributed computing uses multiple devices.

C) Parallel computing is always more efficient than distributed computing.

D) Distributed computing has a speedup metric, while parallel computing does not.

Correct Answer: B

The text defines parallel computing by how it breaks up a program ('broken into multiple smaller sequential computing operations') and distributed computing by its hardware setup ('multiple devices are used to run a program'). This is the most direct comparison based on the definitions provided.

A solution has a 5-second sequential start, followed by two parallel tasks taking 20 and 30 seconds, and a final 10-second sequential step. What is the total execution time?

A) 35 seconds

B) 45 seconds

C) 65 seconds

D) 30 seconds

Correct Answer: B

According to the rule, 'A parallel computing solution takes as long as its sequential tasks plus the longest of its parallel tasks.' The total time is the sum of all sequential parts (5 + 10 = 15 seconds) plus the longest parallel task (30 seconds). Total time = 15 + 30 = 45 seconds.

What is a primary benefit of distributed computing for solving very large problems?

A) It guarantees a solution can be found.

B) It simplifies the programming process.

C) It can solve them quicker than a single computer.

D) It eliminates the need for a sequential portion.

Correct Answer: C

The text states, 'Distributed computing allows much larger problems to be solved quicker than they could be solved using a single computer.'