SOLUTION: I have no idea how to even begin to solve this problem. "It takes Kay 8 days to complete a job working at a constant rate, and it takes Jess 24 days to complete the same job wo

Algebra ->  Rate-of-work-word-problems -> SOLUTION: I have no idea how to even begin to solve this problem. "It takes Kay 8 days to complete a job working at a constant rate, and it takes Jess 24 days to complete the same job wo      Log On


   

Question 743721: I have no idea how to even begin to solve this problem.
"It takes Kay 8 days to complete a job working at a constant rate, and it takes Jess 24 days to complete the same job working at a constant rate, how long would it take Kay and Jess to complete the same job if working together (assuming the effectiveness of both Kay and Jess stays the same)?"
I know they want how long it would take the two girls to finish the job if they worked together, but we only have two numbers. Are we just suppose to average their days out? Please help!
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
You have FOUR numbers. You have a ratio for Kay and a ratio for Jess. Each worker has then, for this job, two numbers. One number is a count of how many days, and the other number is a count of how many jobs --- in this case, 1 job.

See their individual rates:
Kay, 1 job in 8 days. This is 1%2F8 jobs per day.
Jess, 1 job in 24 days. This is 1%2F24 jobs per day.

Their rates are added by simple arithmetic addition when they work at the same time. This means, that working together, Kay+Jess work at the rate of
1%2F8%2B1%2F24 jobs per day.

Once you compute that rate, you may want the reciprocal which will be in the units of DAYS per JOB.