CAT 2025 Slot 3 QA Question 19: The rate of water flow through three pipes A, B and C are in the ratio 4 : 9 : 36. An empty tank can be filled up completely by pipe A in 15 hours. If all the three pipes are used simultaneously to fi

Question

The rate of water flow through three pipes A, B and C are in the ratio 4 : 9 : 36. An empty tank can be filled up completely by pipe A in 15 hours. If all the three pipes are used simultaneously to fi

Accepted Answer

Pipe $A$’s rate corresponds to $4$ parts and fills the tank in $15$ hours.
$	ext{A rate} = \dfrac{1}{15}\ 	ext{tank per hour}$
$	ext{A+B+C rate} = \dfrac{4+9+36}{4} 	imes \dfrac{1}{15}$
$= \dfrac{49}{60}\ 	ext{tank per hour}$
$	ext{Time} = \dfrac{60}{49}\ 	ext{hours}$
$= \dfrac{60}{49} 	imes