SOLUTION: Mike can finish a job in 5 hours. After working for 20 minutes, he requested Ronald to work with him and the two finished the job in 3 hours. How long would it take Ronald alone t

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Mike can finish a job in 5 hours. After working for 20 minutes, he requested Ronald to work with him and the two finished the job in 3 hours. How long would it take Ronald alone t      Log On


   

Question 998268: Mike can finish a job in 5 hours. After working for 20 minutes, he requested Ronald to work with him and the two finished the job in 3 hours. How long would it take Ronald alone to finish the same job?
IS 9 the correct answer?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
RATES
Mike 1%2F5
Ronald 1%2Fx
Both Together 1%2F5%2B1%2Fx

RT=J uniform rates rule to connect rate, time, amount of job.

One-third of an hour Mike worked alone; three hours the two worked together; one whole job done.
highlight_green%28%281%2F5%29%281%2F3%29%2B%281%2F5%2B1%2Fx%29%2A3=1%29

x%2B3%2A3x%2B3%2A15=15x

10x%2B45=15x

45=5x

x=45%2F5=9, as you were asking. YES.