conversations.from: human
conversations.value: Jason waits on a customer whose check comes to $15.00. Jason's state applies a 20% tax to restaurant sales. If the customer gives Jason a $20 bill and tells him to keep the change, how much is Jason's tip?
conversations.from: assistant
conversations.value: First calculate how much the tax is by multiplying $15.00 by 20%: $15.00 * .2 = $3.00
  Then subtract the cost of the meal and the tax from $20 to find Jason's tip: $20 - $15.00 - $3.00 = $2.00