22 questions on percentage change, reverse percentages, simple and compound interest, and depreciation.

💷 Percentages and compound interest

Maths · GCSE Foundation · 22 questions · ~40 min

MathsUKwww.geekhero.co.uk

Percentages appear on all three papers and in more contexts than any other single topic — prices, wages, interest, VAT, population, depreciation. This sheet covers the whole of it in order. It begins with percentage of an amount and percentage change, including finding the percentage rather than applying it; moves to multipliers, which make everything after this easier; then to reverse percentages, where you are given the value after the change and asked for the original, and where subtracting instead of dividing is the commonest error in the topic; then to simple interest, compound interest and depreciation, where the multiplier is raised to a power rather than multiplied by the number of years. The last few questions mix the types without labelling them, because on the paper they are not labelled either.

1.A box holds 80 chocolates. 75% of them are milk chocolates. Work out how many milk chocolates are in the box.
(a)55
(b)75
(c)20
(d)60
2.A laptop costs £720. A carrying case for it costs 1/9 of the price of the laptop. Work out the cost of the carrying case.
(a)£72
(b)£640
(c)£80
(d)£6480
3.2/3 of an amount of money is £30. Work out the amount.
(a)£15
(b)£45
(c)£20
(d)£90
4.A textbook is reduced from £60 to £45. Work out the percentage reduction.
(a)33%
(b)15%
(c)75%
(d)25%
5.A colony of bacteria has 400 bacteria. The number increases by 15% each hour. Work out the number of bacteria after 1 hour.
(a)60
(b)460
(c)340
(d)415
6.A washing machine costs £320 before VAT. VAT is charged at 20%. Work out the total price including VAT.
(a)£340.00
(b)£326.40
(c)£384.00
(d)£64.00
7.After a price increase of 10%, a laptop costs £330. Work out the original price.
(a)£3,300
(b)£300
(c)£363
(d)£297
8.Before a charity campaign, donations were £6400 per month. Donations grew by 8% in the first year after the campaign, and then fell by 3% in the second year as interest faded. Work out the amount donated per month at the end of the second year, to the nearest pound.
(a)£6912
(b)£7104
(c)£6720
(d)£6705
9.A savings account pays 3.5% compound interest each year. Bilal invests £1200. Work out how much interest, in total, he earns after 2 years, to the nearest penny.
(a)£85.47
(b)£1285.47
(c)£84.00
(d)£42.00
10.A jumper is reduced by 15% in a sale to a price of £42.50. Work out the original price.
(a)£283.33
(b)£36.13
(c)£48.88
(d)£50.00
11.Work out 50% of 60.
(a)6
(b)3000
(c)120
(d)30
12.A quiz has 50 questions. Freya answers 10% of them incorrectly. Work out how many questions she answers incorrectly.
(a)5
(b)10
(c)500
(d)45
13.Work out 25% of 200.
(a)50
(b)100
(c)25
(d)800
14.The price of a jacket increases by 50% and then decreases by 50%. Describe the overall change from the original price.
(a)no change
(b)an increase of 25%
(c)a decrease of 25%
(d)a decrease of 50%
15.A box holds 140 pens. 25% of the pens are red. Work out how many of the pens are red.
(a)35
(b)105
(c)25
(d)70
16.40% of a number is 12 more than 25% of the same number. Work out the number.
(a)48
(b)80
(c)15
(d)30
17.A sponsored walk is 36 km long. Aisha has completed 8/12 of the walk. Work out how far she has walked.
(a)288 km
(b)4.5 km
(c)12 km
(d)24 km
18.Work out the difference between 45% of 70 and 35% of 80.
(a)11.5
(b)3.5
(c)59.5
(d)10
19.A charity shop buys a coat for £24 and sells it for a profit that is 3/8 of the buying price. Work out the selling price.
(a)£27.00
(b)£15.00
(c)£9.00
(d)£33.00
20.£3000 is invested in a savings account that pays 4% compound interest each year. Work out the value of the investment after 2 years.
(a)£3244.80
(b)£3120.00
(c)£244.80
(d)£3240.00
21.A population of penguins on an island is 2400. The population is predicted to grow by 7% each year. Work out the predicted population after 2 years, to the nearest whole number.
(a)2568
(b)2736
(c)2747
(d)2748
22.£5000 is invested in an account paying 4% compound interest each year. Work out the total interest earned after 3 years.
(a)£600.00
(b)£408.00
(c)£624.32
(d)£5624.32

What is on this worksheet?

The sheet holds 22 questions drawn from the MathsUK bank — the content areas covered: Ratio, proportion and rates of change, Number (statements R9, R16, N12). It is pitched at GCSE Foundation and takes about 40 minutes to work through in full. It is built for independent practice, with full answers at the end for self-marking.

How to use the sheet well

Print it or open it on screen — both work. Printing is A4; the screen view fits phones and tablets.
Do all 22 questions before checking — about 40 minutes is the guide, but there is no time pressure.
Check the answers — press “Show answers” or print the answer page separately.
Redo the questions you got wrong — twice as effective as doing 22 fresh ones.
“New questions” — builds a fresh sheet on the same statements, so you can practise again without repeats.

Why this sheet helps

MathsUK worksheets use questions graded by difficulty and a fair spread of correct-answer positions (the answer is not always (a)) — so the student really has to think about each question rather than guess a pattern. Every question is tagged to a DfE content statement and checked before it enters the bank. The answers come with a step-by-step explanation, not just a value — so a wrong answer becomes a lesson.

Similar worksheets worth a look

✏️ Paper 1 non-calculator warm-up — Foundation · 20 questions · ~25 min
🎯 Grade 4 pass booster · 25 questions · ~40 min
⚖️ Foundation to Higher crossover check · 20 questions · ~35 min
⚗️ Ratio and proportion mastery — Higher · 24 questions · ~45 min