20 workers working for five hours per day complete a work in 10 days. If 25 workers are employed to work 10 hours per day, what is the time required to complete the work?

- 4 days
- 5 days
- 6 days
- 8 days

**Answer**

Work can be measured in terms of man-days-hours and it remains constant for both sets of workers. So, let days required by second set of workers be = x

So, we have

20 × 10 × 5 = 25 × 10 × x

So, x = 1000 / 250 = 4 days

**The correct option is A.**