A kid is standing in front of a pet store, eagerly watching the animals.
A stranger comes up and says "Kid, I see you want to buy a pet. I'm guessing you have no money. Every kid needs a pet, and I'm willing to pay for one for you, but you have to earn this by using your head!"
"I'm giving you $100 to spend. You must spend it all. I want you to go in and buy 100 animals, at least one of each kind. I see that dogs are selling for $15, cats for $1 each, and hamsters are four for a dollar."
The kid took the money, went into the store, and after some figuring, managed to spend the money and come out with 100 animals. What mixture of animals was purchased?
I give up, show me the solution.