How about 97
2.3
Any two digit number in which: (a) the units digit is not 0, and (b) the two digits are different will form a new 2-digit number when the digits are interchanged.
97
97
It is 97.
97
97
a two digit number is a number that has to digits for example 34 or 78
The largest 4-digit number with two different digits is 9998. Its successor is the next number, which is 9999. However, 9999 has only one digit (9), so we need to find the next valid 4-digit number with two different digits. This number is 10000, which is technically a 5-digit number, so the largest valid number with two different digits before 9999 is 9998, and its successor cannot be a 4-digit number with two different digits. Thus, there is no valid successor that meets the criteria.
A) If a number has two digits, then the sum of its digits is less than the value of the original two-digit number.
50
We generally refer to them by the number of digits. Two-digit number, three-digit number, etc.