33 self-marking GCSE and IGCSE practice questions on Compound interest, written specifically for AQA, Pearson, OCR, Pearson International GCSE Maths A (4MA1), Cambridge IGCSE Mathematics (0580), Cambridge IGCSE (9-1) Mathematics (0980) across Foundation and Higher and Extended tier. Instant marking with full worked solutions on every question.
A few of the 33 questions, from easier to harder. Choose your exam board and tier to practise them, with every answer marked.
Question 12 marksGrade 5-6
Zara invests £3210 in a savings account paying 2% compound interest per year. Work out the total value of the investment after 4 years. Give your answer correct to the nearest penny.
Show the worked solution
Each year the amount is multiplied by 1+1002=1.02
What are the common mistakes in Compound interest?
When a pupil makes one of these on Revision Workshop, the marking engine names the mistake and explains it, instead of just marking the answer wrong.
Misapplies the relationship between the parts of a ratio
Applied the multiplier 5 times instead of 4 times - an off-by-one error in counting the number of years the interest compounds
Adds withdrawals straight back onto a final compound-growth value without reversing the growth applied at each stage
Adds the two withdrawals (£1000 and £1200) straight back onto the final £6103.20 without dividing by 1.02 at each stage, giving £8303.20 instead of correctly reversing the compound interest to get £8000.
Makes a simple arithmetic slip while otherwise following the correct method
Rounded 1.03^-5 incorrectly, or substituted t=5 instead of t=-5, giving a value for the WRONG direction in time.
Quick answers about Compound interest
How many Compound interest practice questions are there?
There are 33 self-marking GCSE and IGCSE Maths questions on Compound interest, written for AQA, Pearson, OCR, Pearson International GCSE Maths A (4MA1), Cambridge IGCSE Mathematics (0580), Cambridge IGCSE (9-1) Mathematics (0980) across Foundation and Higher and Extended tier. Each one is marked instantly and has a full worked solution.
Do I need an account to practise Compound interest?
No. You can start practising Compound interest straight away without an account. A free account keeps your results across sessions, so you can see your progress on this topic over time.
, since compound interest is earned on the total so far (including previous interest), not just on the original amount.
M1
Apply this multiplier once for each of the 4 years: £3210×1.024=£3474.61A1
Question 23 marksGrade 6
A person invests £8000 at a rate of 5% per year compound interest.
Calculate the total amount of interest earned after 3 years.
Show the worked solution
Value after 3 years =8000×1.053=9261. Total interest =9261−8000=£1261. M1M2A1
Question 34 marksGrade 6-7
The value of a house is £120,000. The value is expected to increase by 5% each year.
Work out the expected value after 4 years. Give your answer to 2 significant figures.
Question 43 marksGrade 7-8
Investment A: Save £150 per month for 2 years, then 2.5% interest is added to the total amount saved.
Investment B: Invest £3500. Compound interest is added at 3% per year.
After 2 years, how much more is Investment B worth than Investment A?
Question 54 marksGrade 7
Northern Bank has two types of account, both paying compound interest: a Cash savings account (2.5% per annum) and a Shares account (3.5% per annum).
Ali invests £2000 in the cash savings account. Ben invests £1600 in the shares account.
(a) Work out who will get the most interest by the end of 3 years. You must show all your working.
In the 3rd year the rate of interest for the shares account is changed to 4% per annum.
(b) Does this affect who will get the most interest by the end of 3 years? Give a reason for your answer.
Question 65 marksGrade 8-9
The population of butterflies in a park is 4200.
(a) Assume the population increases by 12% each day. Show that after 20 days the population would be greater than 40,000.
(b) In fact, the population increases by 13% each day for 19 days, then decreases by 8% on the 20th day. After the 20 days, is the actual population greater than 40,000? Show working to support your answer.