It takes 2 hours for faucet A to fill a tank, and it takes faucet B 3 hours. How many hours will it take the faucet to fill the tank together

  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.

t = 3

step-by-step explanation:

put t = 3 in this expression :

(3²-1)(3²-2)(3² - 3)(3² - 4) = 8×7×6×5 = 56×30 = 1680