Question

the hight of the water in an above ground is 3 feet. The pool needs to be drained. As the water changes at a rate of -1/2 inch per mintues it will take to drain the pool

Answer 1

72 minutes.  First convert the height of the pool to inches by multiplying the height in feet by 12 which equals 36.  Next multiply that by 2 because the pool is draining at -1/2 inches per minute, not -1 inch per minute.