A and B can do a certain work in 6 hours, and A, B and C together take 4 hours to do the same. How long will it take for C alone to accomplish the task?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 12 hours.
Calculations:
Total work (LCM of 6 and 4) = 12 units
Efficiency of A and B = 12/6 = 2 units
Efficiency of A, B and C = 12/4 = 3 units
Efficiency of C = A + B + C - A - B = 3 - 2 = 1 units
Required time taken = 12/1 = 12 hours