9 x 8 = 72
155 - 72 = 83
83 divided by 6 =13.8
So he has to make at least 14 deliveries in order to reach his goal.
If i understood the question right, you're trying to find the value when h = -2. If that's true so here is how it's done:

Multiply the denominator by 4
If the pool has 18 married and 22 not married, this means there are 40 people total
this means there’s a 18/40 probability that people who are married will be chosen
18/40 = 2/5
There is a 22/40 probability people who are un married will be chosen
22/40 = 11/20
Ok so there is 60 minutes in an hour and you have 107 minutes so
107-60 = 47 ( 60 has become an hour)
So we are left with 47 minutes, so add the hour to 7:45 which will make it 8:45 pm
Then add 15 to make it 9:00 pm ( 47 - 15 = 32)
And so then add 32 minutes to 9:00 pm
Answer is 9:32 p.m.