Trout are bred in a tank as fish for restaurants.

Twenty trout are caught and each is tagged through the tail then released back into the tank.

A week later, thirty trout are caught and it is found that two of them have a tail tag.

Based on this evidence alone, what estimate can be made of the total number of trout in the tank?

A) 100 B) 300 c) 600 D) 1,200

Question

Trout are bred in a tank as fish for restaurants.

Twenty trout are caught and each is tagged through the tail then released back into the tank.

A week later, thirty trout are caught and it is found that two of them have a tail tag.

Based on this evidence alone, what estimate can be made of the total number of trout in the tank?

A) 100 B) 300 c) 600 D) 1,200

directrix · Answer

I worked this a few minutes ago. http://openstudy.com/users/directrix#/updates/511f3037e4b06821731c5d80

anonymous · Answer

20 trout have tags but when you catch 30 trout only 2 of them have tags

30 divided by 2 = 15
so odds of picking one trout with a tag is 1 in 15

and you know that there are 20 trout with tags. can you work it out from here?