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Left on together, the cold and hot water faucets of a certain buthtub take 7 minutes to fill the tub. If it takes the cold water faucet 17 minutes to fill the tub by itself, how long will it take the hot water faucet to fill the tub on its own?

 Feb 20, 2020
 #1
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A simple google search could've helped you quicker but:

 

7t+119/17t = 1

7t + 119 = 17t            | *17t

119 = 17t - 7t = 10t

t = 11.9

 Feb 20, 2020
 #2
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+1

The portion of the  tub  filled by the coldwater faucet  every minute  = 1/17

 

The portion of the  tub  filled by  both faucets  in one minute  = 1/7

 

So....the portion of the  tub filled by  the  hot water faucet  in one minute   =

 

1/7  - 1/17 =

 

[17 - 7 ] / [7 * 17]  =

 

[10 ] / [ 119]     (1)

 

To find out how long (in minutes) the hot water faucet alone takes to  fil the tub.....take the reciprocal of (1)   =

 

119  /10    =

 

11.9  min

 

 

cool cool cool

 Feb 20, 2020

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