A probability of 0.075 corresponds to a z-score of about

, i.e.
Alright,
you will need to solve for each variable to find if they got the equation correctly or not..
Let's start with h
isolate h
(1/2)h = A/(b1+b2)
Now we need to get rid of 1/2 we may do so by multiplying both sides by 2
h = 2(A/(b1+b2))
And that's not how they did it for h so Option D doesn't apply
Let's see C
Also doesn't apply since they multiplied 2 only by A rather than A/h
Let's see B
Also not correct they made the same mistake as with option C
Let's see A
again same mistake
when multiplying both sides by 2
the 2 should be as following

I believe you should contact your instructor and explain that non of the options is right.
Energy in the form of HEAT
Since these both are on the same hour we'll ignore the 5. We end up having :35 and :52. We'll subtract 35 from 52 which gives us 17. The answer to this is 17 minutes.