To determine the number of deer in a game preserve, a conservationist catches 396 deer, tags them and lets them loose. Later, 627 deer are caught; 209 of them are tagged. How many deer are in the preserve?

Question

To determine the number of deer in a game preserve, a conservationist catches 396 deer, tags them and lets them loose.  Later, 627 deer are caught; 209 of them are tagged.  How many deer are in the preserve?

phi · Answer

This is like having a jar of red and blue jelly beans, and you scoop out one cup.
You find 2 red beans for every 1 blue bean in your cup.  So you should expect to find the same ratio in the big jar.
Same idea here. Use ratios.

anonymous · Answer

1188?

phi · Answer

$$\frac{209}{627}= \frac{396}{total}$$
so, solving for total
$$total= 396\cdot \frac{627}{209}$$
which gives me 1188

anonymous · Answer

Whoo Hoo I got it right!  Thanks for the medal.