Probability of selecting 1 defective item from any 10 =
C(10,1) * (.10) * (.90)^9 = about .3874
Probability of selecting 2 defective items from any 10 =
C(10,2) * (.10)^2 * (.90)^8 = about .1937
So....the probability of getting 1 OR 2 defectives = about .3874 + .1937 = .5811
