Answer:
The correct answer is 10 days.
Explanation:
To fill a trench, 5 men work for 6 hours a day for eight days.
Total work hours required is given by 5 × 6 × 8 = 240 hours.
The same work is supposed to be done by 3 men working 8 hours a day.
Let these three men need to work for x days.
Therefore total work hour these group of three men gave = 3 × 8 × x = 24x hours
Therefore the work hour of both the group of 5 men and 3 men should be equal.
⇒ 24x = 240
⇒ x = 10
Therefore the group of 3 men have to work for 10 days to fill the trench.