A contract is to be completed in 50 days and 105 men were set to work, each working 8 h a day. After 25 days, 2/5th of the work is finished. How many additional men be employed, so that the work may be completed on time, each man now working 9 h a day ?

Explanation:

According to the formula,

M1D1T1\W1= M2D2T2\W2

Given, M1 = 105,D1 = 25,T1 = 8,W1 = 2\5

Now, let the additional men be x.

Then, M2 = 105+x, T2 = 9,D2 = 25

and W2 = 1−2\5=3\5

On putting these values in the above formula,

105×25×8\2/5=(105+x)×25×9\3/5

=> 105×8\2=(105+x)×9\3

=> 105×4=(105+x)×3

=> 105×4=105×3+3x

3x=105

x=35men