Ravina wants to find an estimate for the number of birds in a sanctuary.
She catches a sample of 70 birds in the sanctuary and tags each of these birds.
These birds are then released back into the sanctuary.
The next day she catches a sample of 60 birds in the sanctuary.
Ravina has tagged 12 of these birds.
Verify that an estimate for the number of birds in the sanctuary is 350.
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.