knight247 wrote: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 only 2.5 KM of the road has been completed. Find the number of extra men he must employ to finish the work in time.
(A)43
(B)46
(C)55
(D)68
(E)60
No OA. Detailed explanations would be appreciated. Thanks
(men)(days) / work = (men)(days) / work.
Here is the reasoning behind the proportion above:
A certain number of MEN working for a certain number of DAYS (the numerator) are equivalent to a certain amount of WORK (the denominator)..
In 100 days, 45 men complete 2.5 kilometers.
The road is to be 15 kilometers and must be completed in 300 days total.
We need to determine how many men are needed to complete the remaining 12.5 kilometers in 200 days.
Thus:
(45)(100) / 2.5 = (x)(200) / 12.5
1800 = 16x
x = 112.5.
Since the number of men must be an integer value, the total number of men needed = 113.
Thus, the number of ADDITIONAL men needed = 113-45 = 68.
The correct answer is
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