Marcus wants to estimate the total number of mice in a warehouse.
He catches a sample of 12 mice, marks them and releases them back into the warehouse.
The next night, he takes a second sample of 20 mice.
3 of these mice have been marked.
Work out an estimate for the number of mice in the warehouse.
Write down an assumption you have made.
20 exam-style questions on OCR GCSE Maths Capture Recapture. Each one has a worked solution and a mark scheme showing where the marks go.