Two pumps can fill a water tank in 336minutes when working together. Alone, the second pump takes 6times as long as the first to fill the tank. How many minut

Question

Two pumps can fill a water tank in 336minutes when working together. Alone, the second pump takes 6times as long as the first to fill the tank.

How many minutes would it take the first pump to fill the tank?

Answer 1

x=# minutes it takes the first pump

6x=# minutes it takes the second pump

1/x= rate per minute for the first pump

1/6x= rate per minute for the second pump

(1/x)(336)+(1/6x)(336)=1 (job finished)

(336/x)+(56/x)=1

multiply both sides by x

336+56=x

392=x

x=392 minutes for the first pump to fill the tank (answer)

6x=2352 minutes for the second pump to fill the tank