Guess and Check #11

GC #12

GC #11 hints and answers

A two-digit number is divided by the sum of its digits. What is the largest attainable remainder?

  • One way to go about this might be to list all the 90 possibilities. In other words, 10 divided by 1+0 is 10 with a remainder of 0; 11 divided by 1+1 is 5 with a remainder of 1, and so forth all the way up to 99.
  • But a little thought might give a more systematic approach. Remember, when you divide one number by another, the remainder is always less than the divisor (the number you divide by).

As always, be sure to explain the work you did to arrive at your answers!