Hey

Probability is such a nightmare for me, here's a two part Q I'm struggling with.

A jar contains

**5 red**,

**2 blue** and

**3 green** marbles. What is the probablity of choosing:

a)

*at least one green and at least one red marble*
b)

*at least one red given that at least one green is chosen*
For part B I'm using the formula of Pr(A|B) = Pr(A int B) / (Pr B), but I cannot for the life of me figure out how to get the intersection of "at least one red" and "at least one green".

Help would be much appreciated, thanks all!