A scientist wants to estimate the population of ants in a colony.
She catches 100 ants and marks each one with a tiny dot of paint. She then returns the ants to the colony.
Later that day, she catches another sample of 120 ants. 15 of these ants have a dot of paint on them.
Work out an estimate for the total number of ants in the colony.
Write down any assumptions you have made.
Practise Edexcel GCSE Maths Capture Recapture with exam-style questions for Foundation and Higher tier. 20 questions, matched to the Edexcel GCSE Maths (1MA1) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.