A group of men decided to do a job in 8 days. But since 10 men dropped out every day, the job
got completed at the end of the 12th day. How
many men were at the beginning?
​

Given :

A group of men decided to do a job in 8 days.

10 men dropped out every day, the job  got completed at the end of the 12th day.

To Find :

How  many men were at the beginning ?

Solution :

Let, total number of men initially are n.

It none of them leave, total work :

W = 8n    ...1)

It is given that 10 men are dropped each day it takes them 12 day to complete the work :

W = ( n ) + ( n - 10 ) + ( n - 20 ) +     + ( n - 110 )

W = 12n - ( 0 + 10 + 20 + + 110 )

W = 12n - 660    ...2)

Since, total work is same in both the cases, so equating both equation, we get :

12n - 660 = 8n

4n = 660

n = 165

Therefore, their are 165 men in the beginning.

is the anwser b. (-13)?

i think the answer is b. i hope i !