The Richmond Park gamekeeper wanted to know how many deer were in the park. He caught 90 of them and put a small tag round a hoof of each of them. He then let the deer go back into the park. The next week, the gamekeeper caught 70 deer. 10 of the deer had a tag around one of their hooves.

A) using this information, what estimate did the gamekeeper make for how many deer were in the park ?

B) write down any one assumption he made