Amy and Sally each average 30 km/h for the first hour of a 100 km race. At the end of the hour Amy has a mishap, and loses 12 minutes. Sally finishes the remainder of the race at an average rate of 25 km/h. If Amy averages 27.5 km/h after resuming, will she catch Sally before the finish line? use a diagram to illustrate your answer. Help!

Question

Amy and Sally each average 30 km/h for the first hour of a 100 km race.  At the end of the hour Amy has a mishap, and loses 12 minutes.  Sally finishes the remainder of the race at an average rate of 25 km/h.  If Amy averages 27.5 km/h after resuming, will she catch Sally before the finish line? use a diagram to illustrate your answer. Help!

anonymous · Answer

if they both ran 30km/h, in the first hour, before the mishap, they both went 30 km.

t = distance/speed

t sally = 70km/25km/h = 2.8 hours
t amy = 12 minutes + 70 km/27.5km/h = 0.2 hours + 2.54 hours = 2.74 hours

amy takes less time so she does catch sally. and she wins.

let me know if you have questions