The sum of a 3-digit number and a 1-digit number is 217. the product of the number is 642. if one number is between 200 and 225, what are the numbers?

In this question they are generous enough to give you a set in which your 3-digit number can be, anywhere between 200 and 225. Now, we know the next number is a 1-digit number. Since the product of these numbers is positive, that eliminates the possibility of the 1-digit number being negative. This means your 1-digit number is any number between 0 and 9.

By process of elimination, you can so some simple math to find your answer.

If the 1-digit number is 1: 216+1=217 but 216×1=216, not 624.

If the 1-digit number is 2: 215+2=217 but 215×2=430

Now, if the 1-digit number is 3: 214+3=217 and 214×3=624.

So your numbers are 214 and 3!