2014 · Q3
A, B and C can do a piece of work individually in 8, 12 and 15 days respectively. A and B start working together but A quits after working for 2 days. After this, C joins and works till completion of the work. In how many days will the work be completed?
Elementary MathematicsTime and Work
- A3 8/9 days
- B5 8/9 days
- C5 2/3 days
- D6 1/18 days
Explanation
A and B do 2·(1/8 + 1/12) = 5/12 of the work in 2 days. The remaining 7/12 is done by B and C at 1/12 + 1/15 = 3/20 per day, taking (7/12)/(3/20) = 35/9 days. Total = 2 + 35/9 = 53/9 = 5 8/9 days.