conversations.from: human
conversations.value: I'm completely lost with this math problem: Gail has some bills in her wallet which amount to $100. She has four $5 bills and three $20 bills, and the rest are $10 bills. How many $10 bills are in her wallet?
  Can you give me a hand?
conversations.from: assistant
conversations.value: Four $5 bills amount to $5 x 4 = $20.
  Three $20 bills amount to $20 x 3 = $60.
  So Gail's $5 and $20 bills amount to $20 + $60 = $80.
  Thus, her $10 bills amount to $100 - $80 = $20.
  Therefore, she has $20/$10 = 2 $10 bills.