SOLUTION: It takes a girl 45 minutes to deliver the newspapers on her route; however, if her brother helps it takes only 20 minutes. How long would it take her brother to deliver the newspap

Algebra ->  Rate-of-work-word-problems -> SOLUTION: It takes a girl 45 minutes to deliver the newspapers on her route; however, if her brother helps it takes only 20 minutes. How long would it take her brother to deliver the newspap      Log On


   

Question 347017: It takes a girl 45 minutes to deliver the newspapers on her route; however, if her brother helps it takes only 20 minutes. How long would it take her brother to deliver the newspapers by himself?
Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=amount of time it takes brother to complete route by himself
Then brother works at the rate of 1/x route per min
girl works at the rate of 1/45 route per min
girl and brother working together works at the rate of 1/20 route per min
Sooooooo
1/x + 1/45=1/20 multiply each term by 180x
180+4x=9x
5x=180
x=36 min-----------time it takes brother to complete route alone
CK
1/36 + 1/45= 1/20
5/180 + 4/180=1/20
9/180=1/20
1/20=1/20
Hope this helps---ptaylor