Answer:
24 mph for both 60 miles and 40 miles.
Step-by-step explanation:
We need to find how long it takes to get to college and from it.
Speed x time (x) = Distance (60)
30x = 60
x=2
It takes two hours to get to college
20x = 60
x = 3
It takes 3 hours to get back. It's a total of 5 hours, 2 hours at 30mph and 3 at 20. Now we need to find the average
30+30+20+20+20=120
120/5= 24
The average speed for the round trip is 24.
To do the second part, we follow the same process, but replace 60 with 40 for distance.
30x=40
x= 1.33
20x=40
x=2
We can add the total distance and divide by total time to find the average.
The total distance is 80. Time is 3.33
80/3.33=24
The average speed is still 24.
