How Do You Find the Distinct Digits of a Number?

Get an in-depth explanation about How Do You Find the Distinct Digits of a Number.

As the name says, a 5-digit number compulsorily has 5-digits in it. The smallest 5-digit number is 10,000 and the greatest 5-digit number is 99,999. There are 90,000 five-digit numbers in all.

What is the smallest 2 digit number with unique digits?

10
The smallest 2-digit number is 10 and the greatest 2-digit number is 99.

How many 5 digit numbers are distinct from each other?

Hint: Subtract the number of five-digit positive integers in which all the digits are distinct from the total number of five-digit positive integers. since the leading digit can be chosen in nine ways (as 0 is prohibited) and each of the remaining digits can be selected in 10 ways.

How many numbers have distinct and exactly 2 even and odd?

You need to select two out of five even digits, and two out of five odd digits. The number of ways to do that is ( 5 2) 2 = 100. Then you need to put them in any order. The number of ways to do that is 4! = 24. So the total number of possibilities is 100 ⋅ 24 = 2400. Some of these possibilities have a 0 at the start.

How to find the digits of a number?

Recommended: Please solve it on “ PRACTICE ” first, before moving on to the solution. As the problem is pretty simple, the only thing to be done is :- 1- Find the digits one by one and keep marking visited digits. 2- If all digits occurs one time only then print that number. 3- Else not.

How to count all numbers with unique digits?

Start with state (0,0,0) and count all valid number till we reach number of steps equals to 10 n. This problem can also be solved using a dynamic programming approach and some knowledge of combinatorics.