Final answer:
To find the total number of dogs and cats in the animal shelter, divide the number of puppies by the percentage they represent of the total dog and cat population. The result is the total number of dogs and cats in the shelter.
Step-by-step explanation:
To find the total number of dogs and cats in the animal shelter, we can use the information given about the number of puppies.
Let's assume the total number of dogs and cats in the shelter is x.
Since the puppies are 28% of the total dog and cat population, we can express this as an equation: 0.28x = 21.
To solve for x, divide both sides of the equation by 0.28: x = 21 / 0.28.
Using a calculator, we find that x is approximately 75.
Therefore, there are approximately 75 dogs and cats in the animal shelter.