Discrete or Continuous Problem
Date: 13 Feb 1995 00:56:03 -0500 From: Anonymous Subject: A math question Here's the question. Mae spends $65 a week on food. After 3 weeks she has $415 left in her food budget. What my math class wants to know is: Is this continuous or discrete?
Date: 13 Feb 1995 19:24:48 -0500 From: Dr. Ken Subject: Re: A math question Hello there! I would call this a discrete problem, because the function that tells you how much money Mae has is not a continuous one. It goes down by big chunks of $65. But you can model the situation by a continuous function. If you want to know how much money she started with, let $A be the money she starts with and let f[x] be the function A - 65x. Then you know f = A - 65*3 = 415, so A = 610. Of course, if you want to find out how much money she has after Pi weeks, the formula won't work. But it's good enough when you plug in integers, and it gets the job done. -Ken "Dr." Math
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994-2013 The Math Forum