Multiple choice

A, B and C alone can do a piece of work in 20, 45 and 60 days respectively. They all started the work together, but B left after 5 days. In how many days, was the remaining work completed?

  1. 12.25

  2. 10.75

  3. 9.67

  4. 8.33

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total work = LCM(20,45,60) = 180 units. Rates: A=9, B=4, C=3 per day. In first 5 days: (9+4+3)×5 = 80 units done. Remaining 100 units done by A and C at 12 units/day = 8.33 days. Total days after B left = 8.33.