My number has a tens digit that is 8 more than the ones digit. Zero is not one of my digits.

Answer 1

I presume it's a 2-digit number (though it does not explicitly say so).

The only two pairs of single digits that have a difference of 8, are 1 & 9, and 0 & 8. Since the problem states zero is not one of the digits, we're left with one pair: 1 & 9. The only two-digit numbers that can be made with that pair are 19 and 91. Since the problem says the tens digit is "8 more," not "8 less," that narrows means it can only be 91.

Answer 2

My number has a tens digit that is 8 more than the ones digit. Zero is not one of my digits:

We will assume that the question is asking about a 2-digit number between 1 and 99. The ones digit is a number between 8 and 10. The possible numbers are 8 or 9. But we can't have a zero. So the only solution that satisfies these conditions is :

8+1 = 9

The number is 91.