A garden irrigation system uses 8.7 ml of water per second. The system runs for 56 seconds each time it is activated. The system is activated 28 times over a month.
Work out an estimate for the total volume of water used, in litres.
Is your answer to part (a) an underestimate or an overestimate? Give a reason for your answer.
247 exam-style questions on OCR GCSE Maths Estimating. Each one has a worked solution and a mark scheme showing where the marks go.