A pipe can fill a tank in 6 hours. Another pipe can empty the filled tank in 30 hours. If both the pipes are opened simultaneously, then the time (in hours) in which the tank will be two-third filled, is:

Question

Question

This question was previously asked in

RPF Constable 2024 Official Paper (Held On: 02 Mar, 2025 Shift 1)

Answer 1

Given:

Pipe A can fill a tank in 6 hours.

Pipe B can empty it in 30 hours.

Concept Used:

Total work = Efficiency × Time

Calculation:

Let, 2/3rd of the tank be filled in x hours

According to the question,

⇒ x/6 - x/30 = 2/3

⇒ (5x - x)/30 = 2/3

⇒ 2x/15 = 2/3

⇒ x = 5

∴ The correct answer is Option (2).