Question

A is twice as efficient as B. If A and B together finish a job in 12 days, then number of days required for B to finish the job, is

• A. 18 days
• B. 24 days
• C. 30 days
• D. 36 days

Hint:

When efficiency ratio is given, assume unit efficiencies to simplify calculations.

Answer 1

The Correct Option is D

Concept: Efficiency is directly proportional to work rate. Explanation: Let B’s efficiency = 1 unit Then A’s efficiency = 2 units Together efficiency = 3 units They finish work in 12 days → Total work = $3 \times 12 = 36$ units So, B alone takes 36 days.