Correct Answer - Option 2 : 24
Given:
Ratio of efficiency of inlet pipe to outlet pipe is 2 ∶ 1.
Inlet pipe fills the tank in 12 hours.
Concept used:
Total capacity = LCM of time
Efficiency = (Total capacity)/(Total time)
Calculations:
Let the efficiency of inlet pipe & outlet pipe be '2x' & '1x'.
Total capacity of tank = (Efficiency of inlet pipe) × (Time taken to fill the tank)
⇒ (2x) × 12
⇒ 24x
Time taken to fill the tank by working together
⇒ (Capacity of the tank)/(Combined efficiency)
⇒ (24x)/(2x - 1x)
⇒ 24
∴ The time taken by both the pipes is 24 hours.