A and B can polish the floors of a building in 10 days. A alone can do 
th of it in 12 days. In how many days can B alone polish the floor?
Given,
A and B can polish a building in = 10 days
A alone can do 
of it in 12 days
(A+B)’s 1 day work = 
A’s I day work = 
B’s 1 day work = (A+B)’s 1 day work – A’s 1 day work = 
Thus B can finish the work in = 
days.
11