tzolkin wrote:

I hear more and more about Probability Questions on the GMAT and that some have gotten up to 3 or 4 Questions.

The real Question here is : Just what kind of Probability Questions are being asked ?

Do you have to know

- Hypergeometric Probability Distribution

- The Binomial Probability Distribution

or just Combinations and basic Probability (AND / OR types) ?

On GMAT I've encountered the only probability question like:

You have a box containing 10 balls 4 of which are black. If you pick up 2 of them what is probability that both are black?