Question

A Constructor builds a road 15km long in 300 days and employees 45 man for the purpose. After 100 days he finds that only 2.5 km of the road has been completed. Find how many extra person he has to employee to complete the work in time.

Answer 1

45*100=4500 man days for 2.5 km
The road will take 15/2.5=6 times 100=600 total days to finish or 500 more days
There is already 2.5 finished so for 12.5 km 12.5/2.5=5
so he needs 4500*5 man days. 22500 man days/200 =112.5 men to finish the job in 200 more days.
We can't just hire a half a man so we will need 113 men total 113-45=68 more men.