For this answer it is really going to depend on what you are rounding to. You need to start by dividing 15 by 8. This gives you 1.875 feet. If you are wanting your answer to the nearest hundreth of a foot your answer would be 1.88 feet.
If you are wanting your answer to the nearest tenth of a foot your answer would be 1.9 feet. And if you are wanting your answer to the nearest food your answer would be 2 feet.
let the time taken to be filled by both pipes be y
1/2 +1/8=1/y
(4+1)/8=1/y
5/8=y
cross multiplying
5y=8
y=8/5
=1.6hrs
Answer:
I don't understand percentages