Posted by John on .
There are seven red, five blue, and eight white chips in a bag. What is the probability of pull out a blue or white and then quickly putting it back in the bag and pulling out another blue or white, making a combination of one blue and one white.

Math 
drwls,
That equals the probability of blue followed by white PLUS the probability of white followed by blue.
That would be 2 [(5/20) x (8/20) ]
= 80/400 = 1/5