9514 1404 393
Answer:
A) 29/40
Explanation:
The formula for this is ...
P(A or B) = P(A) + P(B) - P(A and B)
Filling in the given values, you have ...
P(A or B) = 9/20 +1/2 - 9/40
P(A or B) = 18/40 +20/40 -9/40 = (18+20-9)/40
P(A or B) = 29/40 . . . . matches choice A