15% - 40. -25 = 1500 percent take out the zero because they have zero value and your left with 15 which is 15%
Answer:
0.3
Step-by-step explanation:
because there are only one decimal place
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
.