Oliver wants to find an estimate for the number of ants in a colony.
He catches 72 ants from the colony and marks each one with a dye.
He then returns the ants to the colony.
A week later, Oliver catches another 72 ants.
9 of these ants are marked with the dye.
Work out an estimate for the number of ants in the colony.
Write down an assumption 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.