Question

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

Answer 1

Wall Built = 448m;    Time Taken = 27 days;      Men working = 56 men     

Wall built by 56 men in 1 day = 448/27m
Wall built by 1 man in 1 day   = 448/(27x56) = 56/189m

Now,
Wall left to be built = 552m;   Time left = 23 days;   Total men required to complete the rest of work = x

Wall built by x no. of men in 1 day = 56x/189m
Wall built by x no. of men in 23 days =(56*23)x/189 = 1288x/189
Thus,
1288x/189 = 552 (As x no. of men have to build 552m of wall)
1288x = 104328
x = 104328/1288
x = 81 men
Therefore, extra men required = 81-56
                                               = 25 men
Hope that helps!!

Answer 2

Answer:

Step-by-step explanation:

W1 = 448 meter , M1 = 56 , D1 = 27

remaining work ...W2 = 1000 - 448 = 552

M2 = x

Remaining days D2 = 50 - 27 = 23

so M1 * D1 / W1 = M2 * D2 / W2

so 56 * 27 / 448 = x * 23 / 552

x = 81

so extra men = 81 - 56 = 25