SOLUTION: Malik drove his car for 45 miles at an average speed of r miles per hour. On the return trip, traffic has increased and Maliks average speed is 3/4 r. The round trip took a total o
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Question 561463: Malik drove his car for 45 miles at an average speed of r miles per hour. On the return trip, traffic has increased and Maliks average speed is 3/4 r. The round trip took a total of 1 Hour and 45 minutes. Find the average speed for each portion of the trip. Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Malik drove his car for 45 miles at an average speed of r miles per hour.
On the return trip, traffic has increased and Maliks average speed is 3/4 r
The round trip took a total of 1 Hour and 45 minutes.
Find the average speed for each portion of the trip.
:
Change 3/4 to .75
Change 1 hr 45 min to 1.75 hrs
: + = 1.75
multiply by 3r to clear the denominators, results:
3(45) + 4(45) = 3r(1.75)
135 + 180 = 5.25r
315 = 5.25r
r =
r = 60 mph
then
.75(60) = 45 mph for the last part of the trip
;
:
Check this in the time equation + =
.75 + 1 = 1.75 hrs
