Question

To determine the number of trout in a lake, a conversationist catches 141 trout, tags them and trows them back into the lake. Later, 45 trout are caught and 15 are tagged. How many trout would the conversationist expect to be in the lake???

Answer 1

`\begin{gathered} \text{first, the conversationist catched 141 trout}s\text{ and tagged them,} \\ \text{the he catches 45 trouts, but he tagged only 15 of them. That means } \\ 30\text{ of the 45 trouts were already tagged } \\ \text{ so he only found 15 new trouts, and in total he would expect there are } \\ 141+15=156\text{ trouts} \end{gathered}`