Question 435797
The fill rate of pipe 1 = 1/12 pool/hr, and the fill rate of pool 2 = 1/36 pool/hr.
Working together, their combined rate is:
1/12 + 1/36 = 3/36 + 1/36 = 4/36 pool/hr
Taking the reciprocal gives 36/4 = 9 hr/pool
Ans: 9 hours