SOLUTION: Tracy can wallpaper 5 rooms in a new house in 15 hours. Together with her trainee they can wallpaper the 5 rooms in 10 hours. How long would it take the trainee working by herself

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Tracy can wallpaper 5 rooms in a new house in 15 hours. Together with her trainee they can wallpaper the 5 rooms in 10 hours. How long would it take the trainee working by herself       Log On


   

Question 862248: Tracy can wallpaper 5 rooms in a new house in 15 hours. Together with her trainee they can wallpaper the 5 rooms in 10 hours. How long would it take the trainee working by herself to do the job?
Answer by josgarithmetic(39621) About Me  (Show Source):
You can put this solution on YOUR website!
Take care to identify the meaning of "ONE JOB". This job is "wallpaper five rooms". The identification is important.

Tracy's rate, 1/15 jobs per hour.
Trainee's rate, 1/h jobs per hour.
And very carefully, see that Tracy+Trainee, 1/10 JOBS per HOUR. When you understand these, then you are ready to solve for h, the time for the trainee alone to "wallpaper five rooms".

The combined rate is the sum of their individual rates.
highlight_green%281%2F15%2B1%2Fh=1%2F10%29.
Can you solve for h on your own?