Question

12person can do
a piece of work in 12 days . In how many days will 8person finish that work

Answer 1

12person do 1 work in 12days
So 1person do 1/12 work in 12days
So 8 person do 1*8/12 in 12days
8/12 work done in 12 days
So 1work done in 12*12/8
=18days

Answer 2

12 person can do a work in 12 days
1 person can do a work in 12÷12 =1 day
8 person can do a work in 1×8 =8 days