Anu, Vinu and Manu can complete a work alone in 15 days, 12 days and 20 days, respectively. Vinu works everyday. Anu works only on alternate days starting from the first day while Manu works only on alternate days starting from the second day. Then, the number of days needed to complete the work is
Anu, Vinu and Manu can complete a work alone in 15 days, 12 days and 20 days, respectively. Vinu works everyday. Anu works only on alternate days starting from the first day while Manu works only on alternate days starting from the second day. Then, the number of days needed to complete the work is
Solution
When someone can complete work in days, their daily work rate of total work.
Anu's rate per day
Vinu's rate per day
Manu's rate per day
Vinu works every day (Days 1, 2, 3, 4, 5, 6...)
Anu works on alternate days starting Day 1 (Days 1, 3, 5, 7, 9...)
Manu works on alternate days starting Day 2 (Days 2, 4, 6, 8, 10...)
Day 1: Anu + Vinu work together
Work done
Day 2: Vinu + Manu work together
Work done
Every 2 days, total work completed:
After 6 days (3 complete cycles):
Work completed
Remaining work
Day 7: Anu + Vinu work together
Work done
Total work after Day 7:
The work will be completed in 7 days.