P ( S or T ) = P (S) + P(T) - P (P and T)
Since they are mutually exclusive, P( P and T) = 0
So
P (S or T) = P(S) + P(T) = .20 + .22 = .42
5.
We have 22 objects in total
P( Green or Cube) = P(Green) + P (Cube) - P (Green and Cube)
= 11/22 + 12/22 - 5/22
= 18/22
= 9/11
