<prompt> Human: My social studies teacher just blew my mind while teaching the introduction to economics class. It only meets once a week so its only worth 15 the credit. Anyway she says if you buy a 250,000 house and use a 30 year mortgage at 7.5, your payments will add up to 500,000.  <response>: The value of money is relative to time. 500k 30 years from now is worth a lot less than 500k today. 