Question

The smallest 4-digit number is the successor of the largest 3-digit number. True or false? Why?

Answer 1

true,
The smallest 4-digit number is the successor of the largest 3-digit numberthe largest 3-digit number is  999successor of 999 is 1000 = The smallest 4-digit number

Answer 2

The given statement is true.  The "largest 3-digit number is 999", the "successor of largest 3-digit number is 1000".  

The smallest 4-digit number is 1000, whereas the largest 4-digit number is 9999. The successor is generally the next that is the next possible occurrence to the preceding number.

If the "given number" is 9, then the successor for the given number will be 10. This is how it goes for any given value in numerical.

Hence, the smallest 4-digit number is the successor of the largest 3-digit number i.e., 1000. Hence, the given statement is true.