+0  
 
0
2
1
avatar+955 

If Mark drives for 4 hours at 60 miles per hour and then drives another 5 hours at 80 miles per hour, what is his average speed, in miles per hour, for the trip?

 Jan 13, 2024
 #1
avatar+36900 
+1

AVERAGE speed = total distance / total time 

 

total time = 4 = 5 = 9 hrs 

 

then remember    rate * time = distance 

                              60 mi/hr * 4 hr = 240 mi 

                              80 mi/hr * 5 hr = 400 mi       total distance = 640 mi 

 

AVERAGE speed = 640 mi / 9 hr = 71 . 11  mph     ( 71  1/9 mph) 

 Jan 13, 2024

4 Online Users