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Bhanu ChaudharyProfessional
Pipe A can fill a tank in 40 minutes. Pipe B can fill the same tank in 20 minutes. A crack at the bottom of the tank can empty the tank in 120 minutes. If both the pipes are opened simultaneously when the tank is empty and water gets drained through the crack at the bottom, when will the tank be full?
Pipe A can fill a tank in 40 minutes. Pipe B can fill the same tank in 20 minutes. A crack at the bottom of the tank can empty the tank in 120 minutes. If both the pipes are opened simultaneously when the tank is empty and water gets drained through the crack at the bottom, when will the tank be full?·
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Correct Answer: 15 minutes
Pipe A fills 1/40th of the tank every minute. Pipe B fills 1/20th every minute. The crack at the bottom drains 1/120th of the tank every minute.
Therefore, when both the pipes are opened and the crack is left unchecked,
1/40+1/20=1/120th of the tank gets filled.
That is, 3+6−1/120=8/120=1/15th of the tank gets filled every minute.
Hence, the tank will be full in 15 minutes.