conversations.from: human
conversations.value: Andy and Bob went to the canteen to buy snacks. They spent the same amount. Andy bought a can of soda at $1 and two hamburgers at $2 each.  Bob ordered two sandwiches for $3 and a can of fruit drink.  How much did Bob's fruit drink cost?
  Solve it.
conversations.from: assistant
conversations.value: Two hamburger cost 2 x $2 = $4.
  So, Andy spent $1 + $4 = $5.
  Therefore, Bob's fruit drink cost $5 - $3 = $2.