Write the smallest 3-digit number which does not change if the digit are written in reverse order.

Write: the smallest five-digit number?

Write the smallest five digit number?

Write: the smallest four-digit number?

Write all natural numbers between 500 and 600 which do not change if the digits are written in the reverse order.

Write all natural numbers between 500 and 600 which do not change if the digits are written in the reverse order.

Write the smallest 5-digit number having three different digits.

Write the smallest 7-digit number having four different digits.

What is the smallest 3-digit number with unique digits?