ok
Let's think the the convetor is carrying the boxes by their width, so there are
16/8 = 2 boxes
speed = boxes / hour
speed = length / time
length = 96x1
length = 96 in
1 box --------------------- 8 in
x -------------------- 96 in
x = 96/8
x = 12 boxes
Then, in 1 hour it can carry 12 boxes
But it needs to carry 96 boxes
12 boxes -------------------- 1 hour
96 boxes ------------------- x