Question

a can do a piece od work in 25 days and B can finish it in 20 days. they woek for 5 days and then a leaves. inhow many days will B finish the remIning works

Answer 1

Let x= amount of time it will take B to finish the job
A works at the rate of 1/25 of the job per day
B works at the rate of 1/20 of the job per day 
Together A & B work at the rate of 1/25 + 1/20=
4/100 + 5/100= 9/100 of the job per day 
If they both work together for 5 days, they complete (9/100)*5 or 


45/100 of the job, leaving 55/100 of the job yet to be done 
B can do 1/20 of the job per day, so: 
(1/20)*x=55/100 multiply each side by 100
5x=55 divide both sides by 5
x=11 days-----------------amount of time needed by B to finish the job 

Hope this helps!!