CAT 2017 Quantitative Ability

Question : 15 of 34

Marks: +1, -0

A group of workers was put on a job. From the second day on wards, one worker was withdrawn each day. The job was Finished when the last worker was withdrawn. Had no worker been withdrawn at any stage, the group would have Finished the job in 55% of the time. How many workers were there in the group?

Validate

Solution:

It can be solved easily through option

(10+9+8+. . .+1)=10×(10×\;\;{55}/{100})

55= 55

Hence, option (a) is correct.
Alternative Method

n(n+1)/2 = n× {55n}/100

⇒ n =10
In both cases total work is 55 man-days

Go to Question:

Prev Question

Next Question