conversations.from: human
conversations.value: I need a clearer understanding of how to solve: A pet shop has 2 puppies and some kittens. A puppy costs $20, and a kitten costs $15. If the stock is worth $100, how many kittens does the pet shop have?
conversations.from: assistant
conversations.value: The 2 puppies cost 2 * 20 = 40 dollars
  The stock is worth 100 dollars, meaning that the kittens cost 100 - 40 = 60 dollars
  Since the cost of a kitten is 15 dollars, the pet shop has 60/15 = 4 kittens