Question

Left on together the cold and hot water faucets of a certain bathtub takes 6 minutes to fill the tub. If it takes the hot water faucet 15 minutes to fill the tub by itself , how long will it take the cold water faucet to fill the tub on its own ?

Answer 1

10 minutes

Explanation:

We have

1/ hot water faucet + 1/ cold water faucet = 1/6

= 1/15 + 1/c = 1/6

1/c = 1/6 - 1/15

Lowest Common Denominator

= 30

Hence:

1/c = 5 - 2/30

1/c = 3/30

1/c = 1/10

Cross Multiply

c = 10 minutes

Hence, it will take the cold water faucet 10 minutes to fill the tub on its own