Pipes A and B can fill a tank in 15 and 12 minutes respectively. Pipe

1.	Pipes A and B can fill a tank in 15 and 12 minutes respectively. Pipe C can empty the same tank at the rate of 2 liters per minute when the tank is full. If all three pipes are operating at the same time, The tank gets emptied one hour. Tank capacity is1. 14 liters2. 12 liters3. 18 liters4. 16 liters
Answer» Correct Answer - Option 2 : 12 liters Given: Pipe A alone can fill a tank in 12 minutes Pipe B can fill the same tank in 15 minutes Pipe C which is at the bottom of the tank can drain the tank at the rate of 2 litres/minute All three pipes are kept open together when the tank is full, the tank gets emptied in one hour Calculation: Let C be the lime that Pipe C takes to empty the tank when Pipe A and Pipe B are closed Pipe A + Pipe B - Pipe C kept Open together results in a full tank getting emptied in 1 hour (60 min.) ⇒ (1/12) + (/15) - (1/C) = - (1/60) (Negative signed indicates that the tank is getting empty) ⇒ 1/C = (1/12) + (1/15) + (1/60) ⇒ 1/C = (5 + 4 + 1)/60 ⇒ 1/C = 10/60 ⇒ C = 6 minutes If Pipe C can empty the tank in 6 minutes and it drains water at the rate of 2 liters/minute Then the capacity of the tank ⇒ 2 × 6 ⇒ 12 liters ∴ The capacity of the tank is 12 liters

Pipes A and B can fill a tank in 15 and 12 minutes respectively. Pipe C can empty the same tank at the rate of 2 liters per minute when the tank is full. If all three pipes are operating at the same time, The tank gets emptied one hour. Tank capacity is1. 14 liters2. 12 liters3. 18 liters4. 16 liters

Answer» Correct Answer - Option 2 : 12 liters

Given:

Pipe A alone can fill a tank in 12 minutes

Pipe B can fill the same tank in 15 minutes

Pipe C which is at the bottom of the tank can drain the tank at the rate of 2 litres/minute

All three pipes are kept open together when the tank is full, the tank gets emptied in one hour

Calculation:

Let C be the lime that Pipe C takes to empty the tank when Pipe A and Pipe B are closed

Pipe A + Pipe B - Pipe C kept Open together results in a full tank getting emptied in 1 hour (60 min.)

⇒ (1/12) + (/15) - (1/C) = - (1/60)

(Negative signed indicates that the tank is getting empty)

⇒ 1/C = (1/12) + (1/15) + (1/60)

⇒ 1/C = (5 + 4 + 1)/60

⇒ 1/C = 10/60

⇒ C = 6 minutes

If Pipe C can empty the tank in 6 minutes and it drains water at the rate of 2 liters/minute

Then the capacity of the tank

⇒ 2 × 6

⇒ 12 liters

∴ The capacity of the tank is 12 liters