Lesson 4.4.1.8

4.4.1.8 Problem reduction and decomposition Quiz: AQA Computer Science, Unit 4

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 4.4.1.8, Problem reduction and decomposition: 20 multiple choice questions for the AQA Computer Science (7517), Unit 4: Theory of computation, written with Revision Ninja.

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The 20 questions

  1. Transforming a problem until it matches a previously solved problem is called what?

    • Automation
    • Procedural decomposition
    • Problem reduction
    • Data composition

  2. Finding the median of an unsorted list of numbers can be reduced to which problem?

    • Sorting
    • Hashing
    • Matrix multiplication
    • Traversal

  3. Determining whether two words are anagrams can be reduced to which problem?

    • Encrypting
    • Searching
    • Sorting
    • Hashing

  4. Finding the quickest route between two towns on a map reduces to which graph problem?

    • Minimum spanning tree
    • Shortest path
    • Topological sort
    • Graph colouring

  5. Breaking a complex problem into smaller, identifiable sub-problems is known as what?

    • Procedural decomposition
    • Data abstraction
    • Functional abstraction
    • Procedural composition

  6. A program that prints a report is decomposed into 'read data', 'calculate totals' and 'print report'. What is this an example of?

    • Information hiding
    • Automatic garbage collection
    • Procedural decomposition
    • Data encryption

  7. What is the main practical benefit of problem reduction?

    • Reusing existing algorithms
    • Eliminating all testing
    • Automating hardware design
    • Guaranteeing linear time

  8. Replacing complex real-world details with a clean mathematical model is called what?

    • Composition
    • Automation
    • Abstraction
    • Execution

  9. Dividing a software system into distinct input, processing, and output sub-tasks is what?

    • Procedural decomposition
    • Functional abstraction
    • Data composition
    • Automation

  10. Finding the shortest path in an unweighted graph reduces to which search algorithm?

    • Depth-first search
    • Binary search
    • Linear search
    • Breadth-first search

  11. For problem reduction to be useful, what must the reduced problem have?

    • An existing algorithm
    • A graphical interface
    • No parameters
    • A linear complexity

  12. Modelling puzzle states and valid moves as nodes and edges reduces the puzzle to what?

    • A binary tree
    • A graph
    • A stack
    • A queue

  13. Repeatedly breaking sub-problems down into smaller sub-problems creates what structure?

    • A hierarchy
    • A linear array
    • A truth table
    • A circular queue

  14. What technique simplifies a complex problem into one already solved?

    • Load balancing
    • Data mining
    • Problem reduction
    • Deadlock prevention

  15. What is the process of breaking a complex problem down into smaller, manageable sub-problems?

    • Abstraction
    • Decomposition
    • Automation
    • Composition

  16. When reducing a complex problem to a solved problem, what key condition must be checked?

    • Procedural composition
    • Valid reduction
    • Linear time complexity
    • Data abstraction

  17. In procedural decomposition, what should each resulting sub-problem accomplish?

    • An identifiable task
    • A recursive loop
    • A global variable
    • A data structure

  18. What is the main advantage of reducing a problem to a previously solved one?

    • Avoiding composition
    • Removing all variables
    • Reusing existing solutions
    • Eliminating iteration

  19. Which technique involves breaking a complex problem down into smaller, identifiable sub-problems?

    • Problem reduction
    • Decomposition
    • Composition
    • Automation

  20. When sorting player scores while preserving their initial order during ties, which property is required?

    • Recursive sort
    • In-place sort
    • Parallel sort
    • Stable sort

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