# Number of n digit numbers that do not contain 9

Given a number n, find how many n digit number can be formed that does not contain 9 as it’s digit.

Examples:

```Input : 1
Output : 8
Explanation :
Except 9, all numbers are possible

Input : 2
Output : 72
Explanation :
Except numbers from 90 - 99 and all
two digit numbers that does not end
with 9 are possible.

```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Total numbers of n digit number that can be formed will be 9*10^(n-1) as except first position all digits can be filled with 10 numbers (0-9). If a digit 9 is eliminated from the list then total number of n digit number will be 8*9^(n-1).

Below is the implementation of above idea:

## C++

 `// CPP program to find number of n  ` `// digit numbers that do not  ` `// contain 9 as it's digit ` `#include ` `using` `namespace` `std; ` ` `  `// function to find number of  ` `// n digit numbers possible  ` `int` `totalNumber(``int` `n) ` `{ ` `    ``return` `8*``pow``(9, n - 1); ` `} ` ` `  `// driver function ` `int` `main() ` `{ ` `    ``int` `n = 3; ` `    ``cout << totalNumber(n); ` `    ``return` `0; ` `} `

## Java

 `// Java program to find number of   ` `// n digit numbers that do not  ` `// contain 9 as it's digit ` `import` `java.io.*; ` ` `  `public` `class` `GFG ` `{ ` `     `  `// function to find number of  ` `// n digit numbers possible  ` `static` `int` `totalNumber(``int` `n) ` `{ ` `    ``return` `8` `* (``int``)Math.pow(``9``, n - ``1``); ` `} ` ` `  `    ``// Driver Code ` `    ``static` `public` `void` `main (String[] args) ` `    ``{ ` `        ``int` `n = ``3``; ` `        ``System.out.println(totalNumber(n)); ` `         `  `    ``} ` `} ` ` `  `// This code is contributed by vt_m. `

## Python3

 `# python program to find number of n  ` `# digit numbers that do not  ` `# contain 9 as it's digit ` ` `  `# function to find number of  ` `# n digit numbers possible  ` `def` `totalNumber(n): ` `     `  `    ``return` `8` `*` `pow``(``9``, n ``-` `1``); ` `  `  `# driver function ` `n ``=` `3` `print``(totalNumber(n)) ` ` `  `# This code is contributed by Sam007 `

## C#

 `// C# program to find number of   ` `// n digit numbers that do not  ` `// contain 9 as it's digit ` `using` `System; ` ` `  `public` `class` `GFG ` `{ ` `     `  `// function to find number of  ` `// n digit numbers possible  ` `static` `int` `totalNumber(``int` `n) ` `{ ` `    ``return` `8 * (``int``)Math.Pow(9, n - 1); ` `} ` ` `  `    ``// Driver Code ` `    ``static` `public` `void` `Main () ` `    ``{ ` `        ``int` `n = 3; ` `        ``Console.WriteLine(totalNumber(n)); ` `         `  `    ``} ` `} ` ` `  `// This code is contributed by vt_m. `

## php

 ` `

Output:

```648
```

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Improved By : vt_m, Sam007

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