Final answer:
Using a proportion based on the given ratio of cows to horses (5:4) and the number of cows (25), we find that there are 20 horses on the farm.
Step-by-step explanation:
The ratio of cows to horses on the farm is 5:4. To find out how many horses there are when there are 25 cows, you can set up a proportion based on the given ratio. Since the ratio of cows (5) to horses (4) must remain constant, you can write the following:
5/4 = 25/x
Here, x represents the number of horses. To solve for x, you would multiply both sides of the equation by x and then divide both sides by 5 to isolate x:
(5/4) × x = 25,
(4/5) × (5/4) × x = (4/5) × 25,
x = 20.
Therefore, there are 20 horses on the farm.