Lesson R16

R16 Growth, decay, compound interest and iterative processes Quiz: AQA Maths, Unit 3

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson R16, Growth, decay, compound interest and iterative processes: 20 multiple choice questions for the AQA GCSE Maths (8300), Unit 3: Ratio, proportion and rates of change, written with Revision Ninja.

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The 20 questions

  1. £500 is invested at 4% compound interest per year. What is its value after 1 year?

    • £540
    • £504
    • £20
    • £520

  2. What multiplier represents a 3% increase?

    • 1.3
    • 3
    • 1.03
    • 0.97

  3. What multiplier represents a 12% decrease?

    • 0.012
    • 0.12
    • 0.88
    • 1.12

  4. £2000 is invested at 5% compound interest for 3 years. What is its value at the end?

    • £2315.25
    • £2600.00
    • £2250.00
    • £2300.00

  5. A car worth £12000 depreciates by 15% each year. What is its value after 2 years?

    • £9180
    • £10200
    • £7800
    • £8670

  6. A population of 20 000 increases by 10% each year. What is the population after 2 years?

    • 24200
    • 22000
    • 26200
    • 24000

  7. In compound interest, interest is calculated on which amount each year?

    • The original amount plus all interest earned so far
    • The starting amount plus only the simple interest each year
    • Only the interest from the first year, repeated each year
    • The starting amount only, with no interest added on

  8. Which expression gives the value after n years for an initial amount P at rate r%?

    • P(1 + r/100)ⁿ
    • P + nr/100
    • P(1 − r/100)ⁿ
    • P × n × r/100

  9. In exponential decay, what is the size of the multiplier each period?

    • Greater than 1
    • Negative
    • Exactly 1
    • Between 0 and 1

  10. A bacteria population doubles every hour. It starts at 50. How many are there after 4 hours?

    • 200
    • 800
    • 100
    • 400

  11. How many years does £1000 take to grow to £1331 at 10% compound interest per year?

    • 4 years
    • 3 years
    • 2 years
    • 5 years

  12. What term describes a quantity that rises by the same percentage each year?

    • Simple interest
    • Linear growth
    • Exponential growth
    • Arithmetic progression

  13. A machine is worth £5000 and loses 20% of its value each year. What is it worth in 2 years?

    • £4000
    • £3000
    • £3200
    • £2000

  14. £800 is invested at 5% simple interest per year for 4 years. What is the total interest?

    • £200
    • £160
    • £40
    • £168

  15. £500 is invested at 4% compound interest for 2 years. What is its value at the end?

    • £520.00
    • £560.00
    • £540.80
    • £540.00

  16. £250 is invested at 6% compound interest for 2 years. What is its value to the nearest penny?

    • £265.00
    • £280.00
    • £280.90
    • £290.00

  17. (H) A sequence uses x(n+1) = 0.5 × x(n) + 3 with x0 = 0. What are x1 and x2?

    • x1 = 3 and x2 = 6
    • x1 = 0 and x2 = 3
    • x1 = 3 and x2 = 4.5
    • x1 = 1.5 and x2 = 2.25

  18. (H) An iteration uses x(n+1) = 2 + 1/x(n) starting at x0 = 2. What is x1?

    • 4
    • 3
    • 1.5
    • 2.5

  19. (H) Which statement describes an iterative process?

    • Plot points on a graph and join them with a straight line
    • Repeatedly apply a rule, using each result as the next input
    • Use the mean of all the previous results to find the next one
    • Apply a rule once to the starting value and stop

  20. (H) An iteration uses x(n+1) = (x(n) + 6/x(n))/2 starting at x0 = 4. What is x1?

    • 2.75
    • 3.25
    • 4
    • 2.5

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