SOLUTION: Mary left the city for vacation. Sam left three hours later going 41 mph faster to catch up. After 2 hours Sam caught up. What was Mary'd average speed?
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Question 1130739: Mary left the city for vacation. Sam left three hours later going 41 mph faster to catch up. After 2 hours Sam caught up. What was Mary'd average speed? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Mary left the city for vacation.
Sam left three hours later going 41 mph faster to catch up.
After 2 hours Sam caught up.
What was Mary's average speed?
:
let s = Mary's speed
then
(s+41) = Sam's speed
:
From the information given, we know Mary traveled 5 hrs, Sam traveled 2 hrs
:
When Sam catches up with Mary they will have traveled the same distance
Write a distance equation dist = time * speed
5s = 2(s+41)
5s = 2s + 82
5s - 2s = 82
3s = 82
s = 82/3
s = 27 mph is Mary's speed
;
:
Check this: Sam's speed = 27.333 + 41 = 68.333 mph
Find the actual distances, they should be equal
27.33 * 5 = 136.65 mi
68.33 * 2 = 136.66 mi, close enough
