Question

Find the smallest 4-digit number having three different digits.

Answer 1

To get the smallest of 4- digit we have to arrange the digits 0, 1 and 2 in ascending order without 0 at the leftmost place.

So, keeping 1 at the leftmost place, then we can keep 0 at second leftmost place.
Next, to form the smallest 4-digit number using these 3 digits, we have to use 0 twice.
Hence third leftmost digit will be 0, and last digit will be 2.
So the smallest 4-digit number having three digits is 1002.