Question

It takes 4 h for Faucet A to fill a tank, and it takes Faucet B 6 h. How many hours will it take the two faucets to fill the tank together?

Answer 1

Answer:

1.2 hours

Step-by-step explanation:

A fills 1/2 tank per hour; B fills 1/3 tank per hour, so together they fill ...

 1/2 +1/3 = 3/6 +2/6 = 5/6 . . . . tank per hour

The reciprocal of this rate give the rate in the units we want:

 6/5 hours per tank.

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At that rate, it will take 6/5 = 1.2 hours to fill the tank.