If A and B together can complete a work in 4 days, B and C together in 6 days, C and A together in 5 days, then working individually, who will finish the work in the least time and in how many days?
Answer: A, 120/17 days
Explanation:
Let the rates at which A, B and C work be a, b and c respectively.
Therefore,
a + b = ¼
b + c = 1/6
c + a = 1/5
Solving for a, b and c, we get
a = 17/120
b = 13/120
c = 7/120
As we can see, the rate at which A works is the greatest. Hence A would finish the work in the least time and in 120/17 days.