Posted by Anonymous on .
The U.S. Weather Service reports that in a certain northern city it rains 35 days and snows 40 days in the winter. However, it rains and snows on only 10 of those days. Based on this information, what is the probability that it will rain or snow in that city on a particular winter day? Assume that there are 90 days of winter.

algebra 
Chol,
P(A) + P(B)  P(A and B)
35/90 + 40/90 10/90 = 13/18