The pool is filled through two pipes in 6 hours. if water comes only from the first pipe, then it is filled in 10 hours.

The pool is filled through two pipes in 6 hours. if water comes only from the first pipe, then it is filled in 10 hours. How long does it take to fill the pool if water comes only from the second pipe?

The whole pool is -1. The filling rate of the first pipe is x, the second is y. When filling with two pipes, we get the equation (x + y) × 6 = 1. When filling with the first pipe: x × 10 = 1, hence x = 1/10. Substitutes in the first equation – (1/10 + y) × 6 = 1 <=> y = 1/6 – 1/10, bringing to a common denominator 30, we get y = 5/30 – 3/30 <=> y = 2/30 = 1/15. We find the right time, for this the volume of the pool, that is, 1, we divide by the filling rate of the second pipe, we get 1 ÷ 1/15 = 15. Answer: the pool will be filled in 15 hours.