Q. A and B can complete a work in 7 days. A alone can complete it in 21 days. B alone can complete it in?
✅ Correct Answer: (A)
10.5 days
Explanation: 1/7 − 1/21 = 2/21 → time = 21/2 = 10.5 days.
Explanation by: Admin
1/7 − 1/21 = 2/21 → time = 21/2 = 10.5 days.