Question

A contractor undertakes to build a wall 1000 m long in 50 days. He employs 56 men, but at the end of 27 days, he finds that only 448 m of wall is built. How many extra men must the contractor employ so that the wall is completed in time?

Answer 1

Number of men employed in the beginning = 56

Length of wall = 1000 m No. of days = 50

In the time of 27 days, only 448 m of the wall was completed

Remaining period = 50 – 27 = 23 days

and length of wall to be completed = 1000 – 448 = 552

Now in 27 days, 448 m long wall was completed by = 1000 m

in 1 day, 448 m long was completed by = 56 x 27

in 1 day, 1 m long wall will be completed by

`=(56xx27)/448` m

and in 23 days 552 m long wall be completed by

`=(56xx27xx552)/(448xx23)` men

`=(1xx27xx24)/8` = 81 men

∴ No. of extra men required
= 81 − 56 = 25 men