SOLUTION: Two brothers took turns washing the family car on weekends. John could usually wash the car in 45 min, whereas Jim took 30 min for the job. One weekend they were in a hurry to go t

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Two brothers took turns washing the family car on weekends. John could usually wash the car in 45 min, whereas Jim took 30 min for the job. One weekend they were in a hurry to go t      Log On


   

Question 331742: Two brothers took turns washing the family car on weekends. John could usually wash the car in 45 min, whereas Jim took 30 min for the job. One weekend they were in a hurry to go to a football game; so they worked together. How long did it take them?
Answer by mananth(16949) About Me  (Show Source):
You can put this solution on YOUR website!

1/45 + 1/30 of the job they can do in 1 minute
LCD = 1350
75/1350 job they do in 1 minute
they will take 1350 / 75 = 18 minutes to do the job.