Question

A kennel has 80 dogs in total dogs in total, some are puppies and some are adult dogs. The ratio of puppies to adult dogs in a kennel is 3:2. How many puppies are there?

Answer 1

The ratio given says this - 3 puppies : 2 adults = 5 total dogs
You are given (?) puppies : (?) adults = 80 total dogs
In this case, you are trying to find the number of puppies, so you do not need to care about the number of adults. You need to compare the ratio with the actual amount.
Total/puppies = total/puppies
5/3 = 80/(?)
Now, cross multiply. 
5(?) = 240
Divide both sides by 5 and you get your answer.
(?) = 48