The average speed of Christine is 0.125 miles per hour.
Explanation:
At the last practice :
Christine completed a timed run of 1.2 miles in 10 minutes.
- The distance covered, D1 = 1.2 miles.
- The time taken, T1 = 10 minutes.
At the practice before that :
she ran 3.2 miles in 25 minutes.
- The distance covered, D2 = 3.2 miles.
- The time taken, T1 = 25 minutes.
To find the average speed :
"The formula for average speed is total distance divided by total time."
Average speed = (D1 + D2) / (T1 + T2)
⇒ (1.2+3.2) / (10+25)
⇒ 4.4 / 35
⇒ 0.125 miles / hour
∴ The average speed of Christine is 0.125 miles per hour.