6 Pipes fill a tank in 120 minutes, then 5 pipes will fill it in
More the no. of pipes, lesser the time to fill the tank. So, it is an inverse proportion.
Let the required duration be x min.
⇒ 6 × 120 = 5 × x
⇒ x = 
= 144 minutes
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6 Pipes fill a tank in 120 minutes, then 5 pipes will fill it in
More the no. of pipes, lesser the time to fill the tank. So, it is an inverse proportion.
Let the required duration be x min.
⇒ 6 × 120 = 5 × x
⇒ x = = 144 minutes