conversations.from: human
conversations.value: A store offers sandwiches in 3 different package sizes: the first package with 2 sandwiches for $3, the second with 4 sandwiches for $6, and a third with 8 sandwiches, but the price is not indicated. Knowing that the prices are proportional, how much will the package with 8 sandwiches cost?
  What is the solution?
conversations.from: assistant
conversations.value: So the price for 1 sandwich is $3 / 2 sandwiches = $1.5/sandwich
  Now the price for the package with 8 sandwiches would be $1.5/sandwich * 8 sandwiches = $12