I am having trouble finding the probability that 2 mushroom jellyfish will be selected if I am going to draw 2 jellyfish, without replacement, from a tank that contains 5 mushroom jellyfish and 3 cannonball jellyfish. Can anyone help me with this question?

You actually have to calculate two individual probabilities first. Start with the probability that your first pick will be a mushroom jellyfish. Then do the probability that the second pick will also be a mushroom jellyfish (assuming that your first pick was.) Then multiply these two probabilities. The product will be your answer.

Do I need to subtract 2 from each kind and then multiply them together?

There are 8 jellyfish altogether.

The probability of drawing a mushroom jelly is 5/8

The probability of drawing another is 4/7

Thanks for your help. I see now.