Predecessor of a two digit number is always a two digit number.
Step 1: Understand the word “predecessor”.
Predecessor means one less than the given number.
\[ \text{If the number is } n, \] \[ \text{its predecessor is } n - 1. \]
Step 2: Recall what two-digit numbers are.
Two-digit numbers go from 10 to 99.
\[ 10,\ 11,\ 12,\ \ldots,\ 99 \]
Step 3: Test the smallest two-digit number (10).
\[ n = 10 \] \[ \text{Predecessor} = 10 - 1 \] \[ = 9 \]
Here, 9 is a one-digit number.
Conclusion:
We found a counterexample (10 → 9). So the statement “always a two-digit number” is false.
Note: For numbers 11 to 99, the predecessor is two-digit, but the word “always” is not true because of the case 10.