Discussion of Question with ID = 004 under Pipes-and-Cisterns

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A bucket can be filled by a tap in 6 minutes. Another tap on the same bucket can empty it in 15 mins. How long will it take to fill the bucket if both the taps are opened together?


10 mins.


11 mins.


9 mins.


$4{1/3}$ mins.

Ans: a

Net part filling in one hour is $1/x - 1/y$ = $(y - x)/(xy)$. So complete filling occurs in $(xy)/(y - x)$ = ${6 × 15}/{15 - 6}$ = 10 mins.

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