Question 41
A and B complete a work in 20 days. If A alone can do it in 40 days then, then B alone can do half of the same work in ______________ days.
Solution
Let us assume that the work = 40 units.
The efficiency of A = 40/40 = 1 unit per day.
Combined efficiency of A and B = 40/20 = 2 units per day.
B's efficiency comes out to be 2-1 = 1 unit per day and time taken to finish half of the work = 20/1 = 20 days.
