SOLUTION: Events A and B are independent. P(A) = 11/20, P (A or B) =73/100 P(B)=? A)2/5, B)167/200, C)7/20, D) 1/5 I did 73/100=11/20 + p(B) with P(b)=9/50???

Algebra ->  Probability-and-statistics -> SOLUTION: Events A and B are independent. P(A) = 11/20, P (A or B) =73/100 P(B)=? A)2/5, B)167/200, C)7/20, D) 1/5 I did 73/100=11/20 + p(B) with P(b)=9/50???      Log On


   



Question 1078969: Events A and B are independent. P(A) = 11/20, P (A or B) =73/100 P(B)=?
A)2/5, B)167/200, C)7/20, D) 1/5
I did 73/100=11/20 + p(B) with P(b)=9/50???

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
P (a or b)=p(a)+p(b)-p(both)
73/100=55/100+p(b)-(.55*P(b))
9/50=0.45 p(b)=0.18
p(b)=2/5 or .40.
The important part here is that they are said to be independent. That gives the joint probability part. If they were mutually exclusive, 9/50 would work.