If the horse runs for 1 hour(60 minutes) at a constant speed, it will cover a distance of 40 kilometers. 3 minutes is 1/20 of an hour. (60/3)
So in 3 minutes, the horse will run 1/20 of the distance. That is 40/20
= 2 kilometers. Since the horse has completed the race in 3 minutes, the length of the race course is 2 kilometers.
The question can also be solved in the unitary method.
Distance covered in one minute = Distance/Minutes
= 40/60
= 0.67 Kilometers per minute.
So in 3 minutes, the distance covered, which is equal to the length of the race course, = 0.67 * 3 = 2 kilometers.
