To express the ratio of 10 dogs to 4 cats in its simplest form, you need to divide both numbers by their greatest common divisor (GCD).
The GCD of 10 and 4 is 2. By dividing both numbers by 2, we get:
10 ÷ 2 = 5
4 ÷ 2 = 2
Therefore, the simplest form of the ratio 10 dogs to 4 cats is 5:2.