Interactive practice questions
Conservationists previously captured, tagged and released $400$400 whales in a sanctuary. Some time later a large number of whales were observed, and $34%$34% were found to be tagged. Estimate $n$n, the population of the whales in the sanctuary.
Round your answer to the nearest whole number if necessary.
The capture recapture technique was used to estimate the population of cuttlefish. At the beginning of the year the number of cuttlefish caught, tagged and released was $210$210. When $700$700 cuttlefish were taken at the end of the year, $140$140 of them were found to be recaptured tagged ones.
A researcher captures a sample of $400$400 fish in a river, tags them and then releases them. The following day he captures a sample of $1200$1200 fish, of which $100$100 have tags attached to them. Estimate $p$p, the number of fish in the river.
A local council wanted to monitor the number of rabbits in the area. They used the capture-recapture technique to estimate the population of rabbits. $219$219 rabbits were caught, tagged and released. Later, $42$42 rabbits were caught at random. $15$15 of these $42$42 rabbits had been tagged.