In a certain agricultural region the probability of a drought during the growing season is 0.33, the probability of a severe cold spell is 0.32, and the probability of both is 0.19. Find the probability of the following.

a. either a drought or a severe cold spell

b.neither a drought nor a severe cold spell

c. not having a drought

In a certain manufacturing process the probability of a type I defect is 0.13, the probability of a type II defect is 0.23, and the probability of having both types of defects is 0.03. Find the probability of having neither type of defect.

A law firm has thirteen senior and seven junior partners. A committee of 6 partners is selected at random to represent the firm at a conference. What is the probability that at least one of the junior partners is on the committee?