Bunuel
A contractor was required to complete a project in 40 days. The contractor employed 100 workers at the start and then employed another 100 workers after 35 days. The project was completed as required. If the contractor had not employed additional workers, then how much extra time would the project have taken?
(A) 2 days
(B) 3 days
(C) 4 days
(D) 5 days
(E) 6 days
Let the efficiency of the worker be x.
So, amount of work completed by 100 workers in 35days = 35*x*100 = 3500x
So, amount of work left = 1-3500x |eq1
Rest of the work was completed in 5 days by 100 additional workers, so the new equation will be: 5*x*200 =1000x |eq2
Equating eq1 and eq2
1-3500x = 1000x
x = 1/4500
So if no additional worker was hired let's say the work would have been completed in d days.
So, 1/4500 *100*d =1
d = 45 days.
Which is 5 more days than the assigned time.
D is the answer.