SOLUTION: if 'a' can do a job in 4hrs and 'b' can do it in 6hrs, how long will it take if both do it together. and the eqaution to figure it out. ty

Algebra ->  Rate-of-work-word-problems -> SOLUTION: if 'a' can do a job in 4hrs and 'b' can do it in 6hrs, how long will it take if both do it together. and the eqaution to figure it out. ty      Log On


   



Question 319389: if 'a' can do a job in 4hrs and 'b' can do it in 6hrs, how long will it take if both do it together. and the eqaution to figure it out. ty
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Add their rates working separately to get
theirs rates working together
In words:
(1 job/a's time) + (1 job/b's time) = 1 job/working together
1%2F4+%2B+1%2F6++=+1%2Fx
multiply both sides by 12x
3x+%2B+2x++=+12
5x+=+12
x+=+12%2F5
Working together, they can do the job in 2.4 hrs