Question

A contractor undertakes to dig a canal, $6$ kilometers long in $35$ days and employed $90$ men. He finds that after $20$ days only $2$ km of canal have been completed . How many more men must be employed to finish the work in time?

• A. $120$ men
• B. $180$ men
• C. $170$ men
• D. $150$ men

Answer 1

Answer: (D)

Total time given $=35$ days.

To dig a canal of $2$ km in $20$ days, $90$ men were required.

So, to dig a canal of $1$ km in $1$ day, $\frac{90\times 20}{2}$ men will be required.

So, to dig a canal of $4$ km in $15$ days $\frac{900\times 4}{15}$ $=240$ men will be required.

As $90$ men were already employed, so $150$ more men are required.