<span>A warranty identification number has the format: A0000
There are 26 letters in the alphabet. If the identification number has the first digit being 0 then for each letter the number can only go up to A0999. Including A0000, this means there is 1000 combinations per letter. So there is 26,000 possible identification numbers.</span>
Since you are trying to find time, represented by t, you set the equation equal to t. Then you need to add n multiplied by miles, m, to the fixed rate, r.
