<p>Here are a couple of examples where you may find the fence-post formula useful:</p>
<p>(1) How many numbers between 72 and 356 can be expressed as 5x+3, where x is an integer?</p>
<p>(2) Set X contains only the integers 0 through 180 inclusive. If a number is selected at random from X, what is the probability that the number selected will be greater than the median of the numbers in X?</p>