Question

what is the smallest 7 digit number using four different digits

Answer 1

The smallest 7 digit number is 1000000.

In this number there are two different digits only- 1 and 0.

Since it has been asked in the question to write the smallest 7 digit number using 4 different digits.

So, we have to include two different numerical digits instead of repeat usage of 0 and 1. The number is - 1000023.