RRB NTPC · Question 70
A, B and C can complete a job in 40 days, 60 days and 80 days respectively. All the three worked together but A left 11 days and B left 8 days before the completion of work. In how many days, the entire work will be completed?
Show answer & explanation
Answer: (B) 26 days
Explanation
If the work takes n days, A works n − 11, B n − 8 and C n days: (n − 11)/40 + (n − 8)/60 + n/80 = 1. Multiplying by 240: 6n − 66 + 4n − 32 + 3n = 240, so 13n = 338 and n = 26.