We have two responses for you.
Anne,
Average speed is the total distance divided by the total time. Find
out the total time it takes for the circuit. The total distance is 8
miles.
Stephen La Rocque.

Hi Anne,
Average speed is total distance divided by total time. This bicyclist
went 2 miles uphill and 6 miles downhill for a total of 8 miles.
On the 2 mile uphill ride the average speed was 4 miles per hour. How
long did it take?
On the 6 mile uphill ride the average speed was 26 miles per hour.
How long did it take?
What was the total time?
I hope this helps,
Penny
