Query Detail : RBI Grade B Phase I

Some persons undertake to do a work in 32 days , if 4 of them are absent then the rest of group does the work in 40 days, then the original numbers of persons are ? 1.20 2.16 3.12 4.25
Garima,   October 18th 2019,  
RBI Grade B Phase I


Let number of persons = x

So x*32 = (x-4)*40

32x = 40x - 160

8x = 160

x=20