The answers are going to be: D & E
Explanation:
Any number that was multiplied by less then one is going to be your answer. :)
No because they 90 to 200 is 110 but 200 to 325 is 125
110 obviously does not equal 125
The event that either M1 or M2 fails has probability

by the addition rule. Failure events are independent, so

so that

Denote this probability by
. Then
follows a geometric distribution with this parameter
and has density

The expectation is
.