Aptitude Test Interview Questions and Answers (48)

Answer:

(a+b)^2=a^2+b^2+2ab
= 117+2*54=225
=> a+b=15


(a-b)^2=a^2+b^2-2ab
= 117-2*54=9
=> a-b=3



then a+b/a-b
=15/3=5

Answer is 150 men.

Explanation :

1 day work = 2/(7*90)
1 hour work=2/(7*90*8)
1 man work=2/(7*90*8*75)

The Remaing work 5/7 has to be completed in 60 days , because the total number of days allowed for the completion of the work is 150 days.

so we have ,

(2 * 10 * x * 60) / (7 * 90 * 8 * 75) = 5/7
where x is the number of men working after the 90th day.

We get x = 225

Since we have 75 men already,

Answer = 225- 75
It is enough to add only 150 men.