Toby wants to estimate the number of fish in a large pond. He catches a sample of 40 fish, marks them and releases them back into the pond. A week later, he catches a second sample of 50 fish and finds that 8 of these fish are marked.
Work out an estimate for the number of fish in the pond.
Write down any assumptions you have made.
87 exam-style questions on Eduqas GCSE Maths Capture Recapture. Each one has a worked solution and a mark scheme showing where the marks go.