How many Capture-recapture practice questions are there?

There are 12 self-marking GCSE Maths questions on Capture-recapture, written for AQA, Pearson, OCR across Foundation and Higher tier. Each one is marked instantly and has a full worked solution.

Do I need an account to practise Capture-recapture?

No. You can start practising Capture-recapture straight away without an account. A free account keeps your results across sessions, so you can see your progress on this topic over time.

Sampling and populations

Capture-recapture

Q: What are the common mistakes in Capture-recapture?

Added instead of using ratio Swapped ratio terms Combines the three capture-recapture counts by adding/subtracting instead of using the capture-recapture proportion

12 self-marking GCSE practice questions on Capture-recapture, written specifically for AQA, Pearson, OCR across Foundation and Higher tier. Instant marking with full worked solutions on every question.

Start practising Capture-recapture (no account needed)

Sample Capture-recapture questions

A few of the 12 questions, from easier to harder. Choose your exam board and tier to practise them, with every answer marked.

Question 13 marksGrade 4-5
A biologist wants to estimate the number of fish in a pond. On Monday, she catches 60 fish. She puts a tag on each of these fish and returns them to the pond. On Tuesday, she catches 90 fish from the same pond. She finds that 18 of these fish are tagged. Work out an estimate for the total number of fish in the pond.
Show the worked solution
The proportion of tagged fish in the second catch should be about the same as the proportion of tagged fish in the whole population.
$\frac{60}{N} = \frac{18}{90}$

What are the common mistakes in Capture-recapture?

When a pupil makes one of these on Revision Workshop, the marking engine names the mistake and explains it, instead of just marking the answer wrong.

Added instead of using ratio
Added the three given numbers together instead of setting up the capture-recapture ratio $\frac{150}{N} = \frac{40}{200}$

Quick answers about Capture-recapture

How many Capture-recapture practice questions are there?: There are 12 self-marking GCSE Maths questions on Capture-recapture, written for AQA, Pearson, OCR across Foundation and Higher tier. Each one is marked instantly and has a full worked solution.
Do I need an account to practise Capture-recapture?: No. You can start practising Capture-recapture straight away without an account. A free account keeps your results across sessions, so you can see your progress on this topic over time.