Using the values given at the red dot, the horse ran 0.2 miles in 20 seconds.
Divide 1.5 miles by 0.2:
1.5 / 0.2 = 7.5
Multiply that number by 20 seconds:
7.5 x 20 = 150 seconds
1 minute = 60 seconds
150 / 60 = 2.5
It will take 2.5 minutes to run 1.5 miles