SOLUTION: Susan can sort the office mail in 15 minutes but if Kathy helps, they can sort the mail in 8 minutes. How long would it take Kathy to sort the mail alone?

Question 290972: Susan can sort the office mail in 15 minutes but if Kathy helps, they can sort the mail in 8 minutes. How long would it take Kathy to sort the mail alone?
Found 2 solutions by richwmiller, ankor@dixie-net.com:
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
8/15+8/x=1
x=120/7=17.14 alone

Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
Susan can sort the office mail in 15 minutes but if Kathy helps,
they can sort the mail in 8 minutes.
How long would it take Kathy to sort the mail alone?
:
Let k = time required by Kathy to do it alone
Let the completed job = 1
;
A typical shared work equation
+ = 1
Multiply by 15k, results:
8k + 15(8) = 15k
8k + 120 = 15k
120 = 15k - 8k
120 = 7k
k =
k = 17.143 minutes, Kathy alone
:
:
Check solution
8/15 + 8/17.143 =
.533 + .467 = 1
RELATED QUESTIONS
Jose takes twice as long as Maria to sort the mail. Together they can sort the mail in 8... (answered by richwmiller)
Three postal workers can sort a stack of mail in 30 minutes, 30 minutes,... (answered by addingup)
Through postal workers can sort of stack of mail in 10 minutes 15 minutes and 30 minutes... (answered by stanbon)
Three postal workers can sort a stack of mail in 10 minutes, 20 minutes, and 60 minutes,... (answered by josmiceli)
If it takes Matt 20 minutes to sort the mail and 12 minutes if he works with Ryan, how... (answered by richwmiller)
A postal worker can sort a days worth of mail in 8 hours. with her supervisor helping, it (answered by nyc_function)
A postal worker can sort a day's worth of mail in 8 hours. With her supervisor helping,... (answered by ikleyn)
Mr. Samson can sort the bins in 12 days. If Joe Helps him, it takes only 4 days. How... (answered by stanbon)
Mr. Samson can sort the bins in 12 days. If Joe helps him, it only takes 4 days. How long (answered by richwmiller)