Math
posted by Nerd101 .
Runner runs 8 miles at 5 miles per hour, then another 2 miles at 7 miles per hour, find average speed.

Average speed = total distance/total time
time for first leg = 8/5 hrs
time for 2nd leg = 2/7 hours
total time = 8/5 + 2/7 or 66/35
avg speed = 10/(66/35) = 10(35/66) = 5.3 mph
Respond to this Question
Similar Questions

Math
Runner A crosses the starting line of a marathon and runs at an average pace of 5.6 miles per hour. Half an hour later, Runner B crosses the starting line and runs at an average rate of 6.4 miles per hour. If the length of the marathon … 
math
11. Runner A crosses the starting line of a marathon and runs at an average pace of 5.6 miles per hour. Half an hour later, Runner B crosses the starting line and runs at an average rate of 6.4 miles per hour. If the length of the … 
Math
Runner A crosses the starting line of a marathon and runs at an average pace of 5.6 miles per hour. Half an hour later, Runner B crosses the starting line and runs at an average rate of 6.4 miles per hour. If the length of the marathon … 
Math
6. Columbus' ships covered approximately 144 miles a day. How many miles would they have traveled in nine days? 
maths
A motorist travels 120 miles to his destionation at an average speed of 60 miles per hour and returns to the starting point at an average speed of 40 miles per hour.His average speed for the entire trip is 1. 53 miles per hour 2. 52 … 
math
A motorist travels 120 miles to his destination at an average speed of 60 miles per hour and returns at an average speed of 60 miles per hour and returns to the starting point at an average speed of 40 miles per hour. What is his average … 
algebra
A student runs 100 meters in 11 seconds. What is the speed of the student? 
Trigonometry Help!
After one hour in flight, an airplane is located 200 miles north and 300 miles west of the airport. What is the magnitude of the plane's velocity? 
Math College 115
A hiker can walk 2 miles in 43 minutes. What is his average speed in miles per hour? 
Math
On a trip of d miles to another city, a truck driver's average speed was x miles per hour. On the return trip the average speed was y miles per hour. The average speed for the round trip was 50 miles per hour. Show that y=25x/(x25) …