Probability of at least 1....

[sweetkendra]

I am having trouble with this, and it is probably so simple, but math is not my thing.

Suppose you are going to draw 2 jellyfish, without replacement, from a tank that contains 5 mushroom jellyfish and 3 cannonball jellyfish. Find the probability that at least 1 cannonball jellyfish will be selected.

I thought that you would have to subtract 1 from each over the total number, then multiply them together and get an answer, but I am not getting any of the right answers.

4+3+2+1=10/8
2+1=3/8
=30/8 =3 3/4 or 3.75

please help

 

[royhaas]

First find the probability that neither selection is a cannonball jellyfish. Then subtract that from 1.

 

[sweetkendra]

That makes sense, thanks.