A contractor who had a work force of 630 persons, undertook to complete a portion of a stadium in 14 months. He was asked to complete the job in 9 months. How many extra persons had he to employ?
Let work to be done be x
Time taken by 630 persons to complete x= 14 months
x= 630*14=8820
People required to complete the work in 9 months= x/9= 980
Therefore, the contractor had to employ 350 people more to complete the work