SOLUTION: For a certain bathtub, The hot water faucet can fill the tub in 13 minutes. The Cold-water faucet can fill the tub in 7 minutes. If both faucets are used together, how long will

Algebra ->  Human-and-algebraic-language -> SOLUTION: For a certain bathtub, The hot water faucet can fill the tub in 13 minutes. The Cold-water faucet can fill the tub in 7 minutes. If both faucets are used together, how long will       Log On


   

Question 1140426: For a certain bathtub, The hot water faucet can fill the tub in 13 minutes. The Cold-water faucet can fill the tub in 7 minutes. If both faucets are used together, how long will it take to fill the tub?
Found 2 solutions by Alan3354, josgarithmetic:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
For a certain bathtub, The hot water faucet can fill the tub in 13 minutes. The Cold-water faucet can fill the tub in 7 minutes. If both faucets are used together, how long will it take to fill the tub?
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The hot fills 1/13 of the tub/minute.
The cold fills 1/7 per minute.
Together, they fill 1/13 + 1/7 per minute.

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
h, the time for the Hot faucet if used alone
c, the time for the cold faucet if used alone
B, amount of time if both faucets used simultaneously

dimension of fill rate BATHTUB per TIME

1%2FB=1%2Fh%2B1%2Fc
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Assuming to fill 1 bathtub, solve for B.

1%2FB=%281%2Fh%29%28hc%29%2B%281%2Fc%29%28hc%29

1%2FB=%28c%2Bh%29%2F%28hc%29

highlight%28B=%28hc%29%2F%28c%2Bh%29%29
Just substitute from the values in description.