Holly invests £500 \pounds 500\,£500 for 4 years in a bank account. The account pays simple interest at a rate of k% k\%\,k% per year. Work out the total amount of interest Holly has got at the end of 4 years, in terms of kkk.
199 exam-style questions on OCR GCSE Maths Percentages. Each one has a worked solution and a mark scheme showing where the marks go.