conversations.from: human
conversations.value: Melissa bought 4 packs of tennis balls for $24 in total. Each pack contains 3 balls per pack. How much did it cost Melissa for each tennis ball?
conversations.from: assistant
conversations.value: There are 4 packs of tennis balls while each pack has 3 balls. 4 * 3 = 12 balls
  Melissa spent a total of $24 for a total of 12 balls. $24 / 12 = $2 per ball