Question

Biologists want to know how many fish are in a certain lake. on january 1, they removed 600 fish from the lake and tagged them. on february 1, they returned to the lake and collected a random sample of 850 fish, of which 25 had been previously tagged. how many fish does the lake have, based on this experiment?

Answer 1

Biologists collected a random sample of 850 fish and 25 of them had been previously tagged. 850 : 25 = 34. It means that about 1/34 of all the fishes in the lake had been tagged. Therefore 600 * 34 = 20,400.
Answer: Based on this experiment, in the lake lives 20,400 fishes.