Read the problem: A pet shop has 64 dogs and cats altogether. The ratio of the number of dogs to the number of cats is 5:3. The total number of dogs represents what fraction of the animals? The total number of cats represents what fraction of the animals? How many dogs are there altogether? And how many cats are there?
Define the ratio: For every five dogs at the pet shop, there are three cats. This means that if you have 10 dogs, you will have 6 cats. You can also rephrase this as: for every 5x number of dogs, you will have 3x cats, where x is a positive number.
Set up the equation: 5x+3x=64.
Solve: 8x=64
x=8
Find the number of dogs and cats. Dogs: 5x8=40. Cats: 3x8=24.
Find the fraction of dogs and cats out of the total animals. There are 40 dogs out of 64 total animals, or 40/64. Reduce the fraction: 5/8. There are 24 cats out of 64 total animals, or 24/64. Reduce the fraction: 3/8.