An engineer undertakes a project to build a road 15 km long in 300 days and employs 45 men for the purpose. After 100 days, he finds 2.5 km of the road has been completed. Find the (approx.) number of extra men he must employ to finish the work in time.

A. 43

B. 45

C. 55

D. 68

E. 60

Answer: Option D

Solution(By Examveda Team)

Variation Method:
In 100 days only 2.5 km road i.e. 16.66 % of work has been completed

Men	Days	Road (km)
45	100↓	2.5
x↑	200	12.5↑

Arrows show the directions of variation of quantity with respect to each other
$$\frac{{\text{x}}}{{45}} = \frac{{100 \times 12.5}}{{200 \times 2.5}}$$
x = 113 men;
Required men to be increased,
= 113 - 45
= 68