Correct Answer - Option 2 : 36 days
Given∶
Mr. Kunal efficiency = 2(Mr. Aman's efficiency)
Concept used:
Efficiency is inversely proportional to Time
Calculation∶
Let the Mr. Aman completes a work in x days
Then, Kunal completes in (x/2) days
According to question∶
⇒ x - (x/2) = 18
⇒ x/2 = 18
⇒ x = 36 days
∴ Mr. Aman completes a work in 36 days.