Question

A and B can fill build a building in 25 days They work together for 15 days and then B goes away A finishes the work in 20 days how long would each take to finish the work seperately​

Answer 1

Step-by-step explanation:

A+B take 25 days to complete a work it means

A+B both complete 1/25 part of total work in a day

now given A+B worked for 15 days it means 15(1/25) work completed

so remaning work is 1-(15/25) = 10/25

this remaining work is done by A in 20 days

so A alone do (10/25)(1/20) of work per day= 1/50

So A alone do it in 50 days

now we know A+B = 25

let X be no. days B alone can do the work

so (1/50)+(1/X)=1/25

by solving we get X = 50

A do it in 50 days

B do it in 50 days