find how much he will earn
we know he will earn 8 hours sofirst find how many he earns
9 per hour
8 hou
9*8=72
72+6*numberofdeliveries=155
minus 72
6*numberofdeliviers=83
divide by 6
number of delevieries=13.8
he can't make 13.8, round up to get 14
answer is 14 deliveries