Question

To determine the number of trout in a​ lake, a conservationist catches 180 ​trout, tags them and throws them back into the lake.​ later, 48 trout are​ caught; 12 of them are tagged. how many trout would the conservationist expect to be in the​ lake?

Answer 1

The ratio of the trout with tags that are caught and the total trout with tags is first calculated.

     r = 12 trout / 180 trout = 1/15

Then, we divide the number of trouts caught without tag by the value obtained above.

     N = (48 - 12) / (1/15) = 540

Then, we add the number obtained above and 180.
     T = 540 + 180 = 720

ANSWER: 720