# Independant and Disjoint Events

• Oct 16th 2009, 05:23 PM
Sakurazaki
Independant and Disjoint Events
I have managed to figure out the first part, however the second part stumps me. Could someone walk me through this?

http://i30.photobucket.com/albums/c3...titled-1-5.jpg
• Oct 16th 2009, 09:51 PM
mr fantastic
Quote:

Originally Posted by Sakurazaki
I have managed to figure out the first part, however the second part stumps me. Could someone walk me through this?

http://i30.photobucket.com/albums/c3...titled-1-5.jpg

You know that $\Pr(E \cup F) = \Pr(E) + \Pr(F) - \Pr(E \cap F)$ .... (1)

And if E and F are independent you know that $\Pr(E \cap F) = \Pr(E) \cdot \Pr(F)$ .... (2)

Substitute (2) into (1), then substitute the given data and solve for Pr(F).