Im not sure how to translate this word problem about how elk population into a equation.

Question

to determine the size of a park's elk population, rangers tag 15 elk and set them free. months later, 40 elk are caught, of which 12 have tags. estimate the size of the elk population.

Answer 1

Probably a proportion is to be used.

 

15/x = 12/40  reflects the ratio of 15 tagged elks in an unknown population of x.  The 12/40 reflects the ratio observed in the random sample.  Now solve for x.  Hint: you might begin by reducing the 12/40 to lowest terms before cross-multiplying...