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 Malik's average speed is 3/4r. The round trip took a tota

Question 736464: Malik drove his car for 45 miles at an average speed of r miles per hour. On the return trip, traffic has increased, and Malik's average speed is 3/4r. 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 Malik's average speed is 3/4r.
The round trip took a total of 1 hour and 45 minutes.
Find the average speed for each portion of the trip.
:
Change 1 hr 45 min to 1.75 hrs, Change 3/4r to .75r
:
Write a time equation, time = dist/speed
:
+ = 1.75
multiply equation by .75r, to clear the denominators
.75(45) + 45 = 1.75(.75r)
33.75 + 45 = 1.3125r
78.75 = 1.3125r
f = 78.75/1.3125
r = 60 mph
and
.75(60) = 45 mph on the return trip
:
:
Check this find the actual time each way
45/60 = .75 hr
45/45 = 1 hr
---------------
total time 1.75 hrs
RELATED QUESTIONS
Malik drove his car for 45 miles at an average speed of r miles per hour. On the return... (answered by josgarithmetic)

Malik drove his car for 45 miles at an average speed of r miles per hour. On the return... (answered by ankor@dixie-net.com)

Malik drove his car for 45 miles at an average speed of r miles per hour. On the return... (answered by josmiceli)

Please help me solve this applying systems of linear equations word problem! Julie drove (answered by mananth,KMST)

Jerry drove to the airport at an average speed of 45 miles per hour. He returned home... (answered by ankor@dixie-net.com)

Jimmy drove for 80 miles in heavy traffic. He then reached the highway where he drove... (answered by mananth)

Johnny was able to drive an average of 17 miles per hour faster in his car after the... (answered by ankor@dixie-net.com,KMST)

A family drove 1080 miles to their vacation lodge. Bercause of increased traffic... (answered by RAY100)

A family drove 1080 miles to their vacation lodge. Bercause of increased traffic... (answered by RAY100,ptaylor)