Question

Events A and B are mutually exclusive. Find the missing probability.

P(B) = 7/20 P(A or B) = 7/10 P(A) = ?
A) 3/5 B) 7/20 C)4/5 D) 1/5

Answer 1

B, 7/20

Explanation:

If two events are mutually exclusive that means that there is no intersection

so in the union formula: AUB=A+B-A∩B

A∩B=0

we can write P(a)=x

7/10=7/20+x+0

7/10-7/20=x

x=7/20