Originally Posted by WiredGuy

Ok, I'm in a good mood.
First off your first answer is wrong.


It's not 0.80, you don't just add the first 2 probabilities and ignore the second set of data given. You need to multiply the 2 probabilities and then sum them up:

So, (0.60 * 0.20) + (0.20 * 0.80) + (0.20 * 0.20) = .12 + .16 + 0.4 = 0.68

So you actually have a 68% chance of discovering oil now.
PS: It's been 2 years since I did stats, so don't hold me to this answer. If you fail, its your own fault for not paying attention in class.

WG