A, B and C can do a work separately in 15, 30 and 45 days respectively. They started the work together but B and A left 4 days and 5 days respectively before the completion of the work. In how many days was the work finished ?
Answer & explanation
Correct answer: option 2
Let us assume , Extra work done by A and B if they work for 5 days and 4 days more
A = 6R × 5 = 30R
B = 3R × 4 = 12R
Total work = 90R + 30R + 12R = 132R
Total work = Efficiency × Number of days
Time taken = \(\frac{132}{11}\) = 12 days