SOLUTION: A driver makes a 124 mile trip from Phoenix to Tucson with the cruise control set at either 55 mph or 75 mph the whole way. If the trip took 2 hours, how long did the driver travel
Question 454132: A driver makes a 124 mile trip from Phoenix to Tucson with the cruise control set at either 55 mph or 75 mph the whole way. If the trip took 2 hours, how long did the driver travel at 55 mph? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! A driver makes a 124 mile trip from Phoenix to Tucson with the cruise control set
at either 55 mph or 75 mph the whole way.
If the trip took 2 hours, how long did the driver travel at 55 mph?
:
Let x = time driven at 55 mph
the total time was given as 2 hrs, therefore:
(2-x) = time driven at 75 mph
:
Write a dist equation: dist = speed * time
:
55x + 75(2-x) = 124
55x + 150 - 75x = 124
55x - 75x = 124 - 150
-20x = -26
x =
x = 1.3 hrs at 55 mph hr
:
:
:
Check solution by finding the distance at each speed
55(1.3) = 71.5 mi
75(2-1.3)= 52.5
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total dist 124 mi
