A box is filled with 6 blue cards, 3 brown cards, and 3 red cards. A card is chosen at random from the box. What is the probability that the card is not brown?
There are two ways to do the problem. Take your pick. But you should know how
to do it both ways, because sometimes it's easier to do it one way and sometimes
it's easier to do it the other way:
Method 1. P(not a brown card) = P(a blue card OR a red card) =
P(blue card) + P(red card) = = =
Method 2. P(not a brown card = 1 - P(brown card) = 1 - = 1 - = =
Either way, you get .
Edwin