Correct Answer - Option 4 : 2.4
Given:
The efficiency of C to complete a work is 3 times more than the efficiency of A to complete the work. B can finish the work in the same time as A and C together finish the work. If A takes 12 days to finish the work.
Formula:
If A and B can together finish it in t days with A and B finishing the work in a and b days respectively,
1/a + 1/b = 1/t
Calculation: C A
Efficiency 4 1
Days 1 4
A takes 12 days to finish the work
Total work = 12 × 1 = 12
Time taken by A and C = total work/efficiency = 12/4 + 1 = 12/5 = 2.4 days
So, B will take 2.4 days
