SOLUTION: Lester and Ralph work in an athletic shoe store in the mall. When they goof off too much their boss punishes them by making them lace-up all of the inventory. If it takes Lester 30

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Lester and Ralph work in an athletic shoe store in the mall. When they goof off too much their boss punishes them by making them lace-up all of the inventory. If it takes Lester 30      Log On


   

Question 1159116: Lester and Ralph work in an athletic shoe store in the mall. When they goof off too much their boss punishes them by making them lace-up all of the inventory. If it takes Lester 30 sec to lace-up a high top and Ralph 35 seconds to do the same, how many seconds will it take them to lace-up 260 high top shoes?
Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


Consider the least common multiple of the two given times, which is 210 seconds.

In 210 seconds, Lester can lace up 210/30 = 7 shoes, and Ralph can lace up 210/35 = 6 shoes. So in every 210 seconds the two of them can lace up 7+6=13 shoes.

They need to lace up 260 shoes. 260/13 = 20; so the amount of time it will take them to lace up the 260 shoes is 20*210 = 4200 seconds, or 70 minutes.