SOLUTION: A person drove for 6 hours at an average speed of 45 miles per hour and for 9 hours at an average speed of 55 mph. Find the average speed for the entire trip. (I tried 45/6 + 55/
Algebra.Com
Question 651287: A person drove for 6 hours at an average speed of 45 miles per hour and for 9 hours at an average speed of 55 mph. Find the average speed for the entire trip. (I tried 45/6 + 55/9 =100/15. 15 divided into 100 = 66...is answer 66 mph? Don't think so.)
Answer by MathTherapy(10559) (Show Source): You can put this solution on YOUR website!
A person drove for 6 hours at an average speed of 45 miles per hour and for 9 hours at an average speed of 55 mph. Find the average speed for the entire trip. (I tried 45/6 + 55/9 =100/15. 15 divided into 100 = 66...is answer 66 mph? Don't think so.)
Wrong, wrong, wrong approach!! You're right....it's not so, at all. See below!!
Distance covered at 45 mph for 6 hours = 45 * 6, or 270 miles
Distance covered at 55 mph for 9 hours = 55 * 9, or 495 miles
Total distance traveled = 270 + 495, or 765 miles
Total time taken to travel 765 miles = 6 + 9, or 15 hours
Average speed = total distance, divided by total time
Average speed for entire trip = , or mph
Send comments and “thank-yous” to “D” at MathMadEzy@aol.com
RELATED QUESTIONS
a car drove at an average speed of 37 miles per hour for 9 hours how far did it... (answered by Alan3354)
Mr. Hoffman drove from Indianapolis to Atlanta on business. The distance between the... (answered by ikleyn)
Katie drove 2 1/2 hours at an average speed of 55 miles per hour and 1 1/2 hours at an... (answered by macston)
Diane drove her car at an average speed of 45 miles per hour for 3.2 hours . How far did... (answered by ramkikk66,Awesom3guy)
William drove 5 hours at the average speed of 54 miles an hour. For the first 2 hours, he (answered by mananth)
A can travels for two hours at an average speed of 40 miles per hour. For how long must... (answered by scott8148)
A van travels for two hours at an average speed of 40 miles per hour. For how long must... (answered by stanbon)
A van travels for two hours at an average speed of 40 milles per hour. For how long must (answered by ptaylor)
Sharlene drove an average of 45 miles per hour for 3 hours and then 60 miles per hour for (answered by Boreal)