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| Question 1100086:  1. Mary departs for school on a bicycle at an average rate of 6 miles per hour. Her sister Kate, running late, leaves 15 minutes later and cycles at twice that speed. How long will it take Kate to catch
 Answer by ankor@dixie-net.com(22740)
      (Show Source): 
You can put this solution on YOUR website! 1. Mary departs for school on a bicycle at an average rate of 6 miles per hour. Her sister Kate, running late, leaves 15 minutes later and cycles at twice that speed.
 How long will it take Kate to catch Mary?
 :
 We are dealing in mph, change 15 min to .25 hrs
 let t = Kate's travel time
 then
 (t+.25) = Mary's travel time
 :
 When K catches M, they will have traveled the same distance
 Write a distance equation, dist = speed * time
 12t = 6(t+.25)
 12t = 6t + 1.5
 12t - 6t = 1.5
 6t = 1.5
 t = 1.5/6
 t = .25 hrs or 15 min for K to catch M
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