0.8 is greater than 0.08, the reason for that is that 0.8 is equal to 8/10=80/100 and 0.08 is equal to 8/100. As a percentage, 0.8 would be 80% and 0.08 would be equal to 8%.
The probability of finding one of the two defective fuses is:

The probability of finding 2 defective fuses is:

Therefore the probability of rejecting is 0.3117 + 0.026 = 0.3377.
I believe that the answer is 7/18, at least that’s what I got.
A: -15/5 degrees Celsius
B: -15/5=3 degree Celsius
every 5 weeks it change -15°c
so each week it changes -3°c