Problema Solution
A faucet can fill a bathtub in 9 mins.The drain can empty the full tub in 12 mins. With the drain open and the faucet on, how long would it take to fil the tub?
Answer provided by our tutors
Let 'x' represent the time (in minutes) needed for the tub to fill with water with the rain open and the faucet on.
1/x tub per min is the rate when the drain is open and the faucet is on.
The faucet's rate is 1/9 tubs per min.
The drain's rate is 1/12 tubs per min.
1/9 - 1/12 = 1/x
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click here to see the equation solved for x
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x = 36 min
It will take 36 minutes for the tub to fill when the drain is open and the faucet is on.