SOLUTION: Fred can repair the roof in 4 hours. If Sandy helps, it takes them 3 hours. Without help, how long would it take for Sandy to repair the roof?
Algebra.Com
Question 911995: Fred can repair the roof in 4 hours. If Sandy helps, it takes them 3 hours. Without help, how long would it take for Sandy to repair the roof?
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
rate for A alone 4
rate for A & B together 3
1/a+1/b=1/x
1/4+1/b=1/3
1/b=1/3-1/4
1/b=4/12-3/12
1/b=1/12
1/b=1/12
b=12
rate for B alone 12
check
1/4+1/12=1/3
12/48+4/48=1/3
16/48=1/3
ok
codewa
RELATED QUESTIONS
Benny can clean attic in 8 hours. If Donna helps, it takes them 5 hours. Without help,... (answered by josmiceli,macston)
Sam can wash a boat in five hours, If Mary helps, it takes them three hours. Without... (answered by solver91311)
Marie can paint a room in 9 hours. If Ana helps, it takes them 7 hours. Without help, how (answered by Boreal)
It takes a professional 7 hours to repair a roof. Working together, you and the... (answered by stanbon,scott8148)
Sandy can complete her paper route in 45 min. When her sister Kris helps her. it takes... (answered by solver91311)
Tim can spread mulch in 12 hours. If Nancy helps, it can take them 8 hours. Without Tim's (answered by harpazo)
karla, pam, and sandy working together can do a job in two hours. karla and pam working... (answered by ankor@dixie-net.com)
Jazmine can mow her lawn in 3 hours. If Sade helps, it takes 2 hours. How long would it... (answered by jim_thompson5910)
It takes Bob 4 hours longer to repair a car than it takes Ken. Working together, they can (answered by checkley79,nerdybill)