conversations.from: human
conversations.value: Sarah has a rope that is 20 meters long. Her friend wants to buy the rope for $2 a meter. Sarah plans to use the profit to buy a new rope, which at the store costs $1.5 a meter. How much money will she have left over after she buys the new rope?
conversations.from: assistant
conversations.value: Her friend pays her $40 for the rope because 20 x 2 = 40
  She can buy the rope at the store for $30 because 20 x 1.5 = 30
  She has $10 left over because 40 - 30 = 10