A and B can polish the floors of a building in 25 days. `A` alone can do 13 of this job in 15 days. In how many days can B alone polish the floors of the building?

Explanation

A and B can polish the floors in `25` days.
A alone can do `1/3` of this job in `15` days.
Work rate of A and B = `100/25 = 4%`' per day.
A alone can do `1/3 (33.33%)`of work in `15` days.
Thus, Work rate of 'A = `33.33/15`
= `2.22%` per day.
Work rate of B = `4 - 2.22`
`= 1. 78%` per day.
Therefore, alone Bcan polish the floor = `100/1.78 `
= `56.17` days.