conversations.from: human
conversations.value: I'm completely lost with this math problem: A store sells pencils and erasers. It has a rule that for every pencil you buy, you must buy 2 erasers which cost 1/2 the price of the pencils. If they sold 20 pencils and earned $80, how much do erasers cost?
  Can you give me a hand?
conversations.from: assistant
conversations.value: They sold 40 erasers because 20 x 2 = 40
  Therefore 20(Pencil Price) + (1/2)(40 x Pencil Price) = 80
  Therefore 40(Pencil Price) = 80
  Therefore (Pencil Price) equals 2 because 80 / 40 = 2
  An eraser costs $1 because 2 / 2 = 1