math questions

Question

To estimate the number of Bass in a lake, wildlife biologist tagged 50 bass and released them in the lake. Later they netted 108 bass and found that 27 of them were tagged.  Find how many bass are in the lake

Answer 1

You can set up a proportion to estimate how many bass are in the lake. Let x = number of bass in the lake. 27 out of the 50 tagged bass were netted, and that proportion should be roughly equal to the proportion of total bass in the lake that were netted (108 out of x). In other words:

 

27 / 50 = 108 / x

 

Solve by cross multiplying and then simplifying:

 

27x = 50(108)

27x = 5400

x = 200 bass