question: Tom bought a CD for $4, and a headphone set. In total, he paid $48. How many more CDs would Tom have been able to buy if he had decided not to buy the headphone set?
answer: The headphone set cost was 48 - 4 = $<<48-4=44>>44.
  That means, for that money Tom would be able to buy 44 / 4 = <<44/4=11>>11 more CDs.
  #### 11