SOLUTION: Krystal can wax a floor in 16 minutes. One day her friend Perry helped her and it only tool 5.76 minutes. How long would it take Perry to do it alone?

Question 198755: Krystal can wax a floor in 16 minutes. One day her friend Perry helped her and it only tool 5.76 minutes. How long would it take Perry to do it alone?
Found 2 solutions by user_dude2008, josmiceli:
Answer by user_dude2008(1862) (Show Source): You can put this solution on YOUR website!
5.76(1/16+1/x)=1

0.36+5.76/x=1

5.76/x=1-0.36

5.76/x=0.64

5.76=0.64x

5.76/0.64=x

Answer: x=9

Perry can do it in 9 min alone
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
This is a problem of adding 2 rates to get a combined rate
In words,
Krystal's rate of working is (1 floor waxed)/(Krystal's time for 1 floor)
Perry's rate of working is (1 floor waxed)/(Perry's time for 1 floor)
and
If I add these rates to get a rate working together,
Krystal and Perry's rate of working is (1 floor waxed)/(K & P time for 1 floor)
and
The problem says that working together, (1 floor waxed)/(5.76 min)
Krystal's rate of working is (1 floor waxed)/ (16 min)
Let = Perry's time to wax 1 floor working alone

Multiply both sides by

Multiply both sides by

Multiply both sides by

Perry, working alone, can wax the floor in 9 minutes
check answer:

OK
RELATED QUESTIONS
Hi there, I would appreciate some help with the next problem: Kristal can wax a... (answered by ewatrrr,htmentor)
Linnette can wax a floor in 25 minutes. One day her friend Shanika helped her and it only (answered by ikleyn)
Nicole can sweep a porch in 11 minutes. One day her friend Asanji helped her and it only... (answered by josgarithmetic)
Elisa can pick forty bushels of apples in ten hours. One day her friend Huong helped her... (answered by richwmiller)
Working alone, Elisa can dig a 10 ft by 10 ft hole in nine hours. One day her friend... (answered by Boreal,josgarithmetic)
Karen can wax her SUV in 3 hours. Her friend Gus can wax her SUV in 2 hours. How long... (answered by richwmiller)
Rob can tar a roof in nine hours. One day hsi friend Kayla helped him and it only took... (answered by ankor@dixie-net.com)
James can mop a warehouse in 12 hours. One day his friend Molly helped him and it only... (answered by lwsshak3)
Janet can wax her car in 8 hours. When she works together with Darlene, they can wax the... (answered by josmiceli)