Question

Andreas wants to estimate how many fish there are in a lake. One day he catches 20 fish,marks them,and returns them to the lake. The next day he catches 10 fish of which four are marked. Estimate the number of fish in the lake.

Answer 1

50

Explanation:

The ratio of marked fish to caught fish is 4:10, we need to solve for x in 20:x, since 4 * 5 = 20, 10 * 5 = x so x = 50 fish.