Question : A, B, and C can complete a work in 10, 12, and 15 days respectively. They started the work together, but A left the work before five days of its completion. B also left the job two days after A left. In how many days was the work completed?
Option 1: 4 days
Option 2: 5 days
Option 3: 7 days
Option 4: 8 days
Correct Answer: 7 days
Solution :
A left the work 5 days before completion.
B left the work 3 days before completion.
We know that Total work = Number of days × Efficiency of work.
Let the number of days required to complete the whole work =
1 day work of A =
1 day work of B =
1 day work of C =
According to the question,
Hence, the correct answer is 7 days.
