SOLUTION: robot A can weld a fender in 5 minutes, another can finish it in 3 minutes. Robot A starts welding for two minutes, then the other helps finish. how much longer does it take to fin

Algebra ->  Rate-of-work-word-problems -> SOLUTION: robot A can weld a fender in 5 minutes, another can finish it in 3 minutes. Robot A starts welding for two minutes, then the other helps finish. how much longer does it take to fin      Log On


   

Question 451755: robot A can weld a fender in 5 minutes, another can finish it in 3 minutes. Robot A starts welding for two minutes, then the other helps finish. how much longer does it take to finish the fender?
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
robot A can weld a fender in 5 minutes, another can finish it in 3 minutes. Robot A starts welding for two minutes, then the other helps finish. how much longer does it take to finish the fender?
..
let x=minutes longer to finish the fender
Robot A work rate=1/5
Helper robot work rate=1/3
Helper robot works for x minutes
Robot A works for x+2 minutes
(1/5)(x+2)+(1/3)x=100% of job=1
LCD=15
3x+6+5x=15
8x=9
x=9/8 minutes
ans:
It takes 9/8 minutes longer to finish the fender