Question

The U.S. Weather Service reports that in a certain
northern city it rains 40 days and snows 50 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.)

Answer 1

probability of rain or snow=(40/90)+(50/90)-(10/90)=8/9