Question

What will be the successor of the greatest 7-digit number and the predecessor of the smallest 8-digit number? Is there any relation between these two numbers? If yes, state the relation.

Answer 1

The largest 7-digit number, is a 7 nine digits, this number is:

9,999,999

If we subtract one, we get a 7-digit number smaller than this one.

if we add one, we get an 8-digit number.

Then this one is the greatest 7-digit number.

The successor of this number, is equal to the number plus one:

9,999,999 + 1 = 10,000,000

The smallest 8-digit number is the first 8-digit number, and we know that this one is:

10,000,000

And the predecessor is equal to this number minus one:

10,000,000 - 1 = 9,999,999

So we can conclude that:

The successor of the greatest 7-digit is the smallest 8-digit number

The predecessor of the smallest 8-digit number is the greatest 7-digit number.

And we could interpolate this for any N-digit number, such that:

The successor of the greatest N-digit is the smallest (N + 1)-digit number

The predecessor of the smallest (N + 1)-digit number is the greatest N-digit number.