SOLUTION: A and B working together can finish the job alone in 3 hours , while A can finish the job alone in 5 hour . what fraction of the job does A do , when A and B work together ?

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: A and B working together can finish the job alone in 3 hours , while A can finish the job alone in 5 hour . what fraction of the job does A do , when A and B work together ?       Log On


   



Question 1096230: A and B working together can finish the job alone in 3 hours , while A can finish the job alone in 5 hour . what fraction of the job does A do , when A and B work together ?

Found 2 solutions by jorel1380, MathTherapy:
Answer by jorel1380(3719) About Me  (Show Source):
You can put this solution on YOUR website!
Let a and b be the amount of time it takes A and B, respectively, to finish the job alone. Then:
1/a + 1/b=1/3
a=5, so:
1/5 + 1/b=1/3
1/b=1/3 - 1/5=5-3/15=2/15
b=15/2 hours alone
So, in doing one job, A does 3/5 of the work, and B does 3 x 2/15=6/15=2/5 of the work
☺☺☺☺

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

A and B working together can finish the job alone in 3 hours , while A can finish the job alone in 5 hour . what fraction of the job does A do , when A and B work together ?
It's right there!
A can do the job in 5 hours or 1%2F5 of job in 1 hour
They work for 3 hours, together, so during those 3 hours, A can do highlight_green%28matrix%281%2C6%2C+3%281%2F5%29%2C+or%2C+3%2F5%2C+of%2C+entire%2C+job%29%29