A 6-hour rainfall of 6 cm at a place A was found to have a return period of 40 years. The probability that a 6 hour rainfall of this or larger magnitude will occur at least once in 20 successive years is:

A 6-hour rainfall of 6 cm at a place A was found to have a return peri

1.	A 6-hour rainfall of 6 cm at a place A was found to have a return period of 40 years. The probability that a 6 hour rainfall of this or larger magnitude will occur at least once in 20 successive years is:
A.	0.308
B.	0.015
C.	0.605
D.	0.397
Answer» E.