C program to check whether a number is divisible by 5 and 11 or not

Write a C program to check whether a number is divisible by 5 and 11 or not using if else. How to check divisibility of any number in C programming. C program to enter any number and check whether it is divisible by 5 and 11 or not. Logic to check divisibility of a number in C program.

Input number: 55

Number is divisible by 5 and 11

Required knowledge

Basic C programming, Arithmetic operators, Relational operators, Logical operators, If else

Logic to check divisibility of a number

A number is exactly divisible by some other number if it gives 0 as remainder. To check if a number is exactly divisible by some number we need to test if it leaves 0 as remainder or not.

C supports a modulo operator %, that evaluates remainder on division of two operands. You can use this to check if a number is exactly divisible by some number or not. For example – if(8 % 2), if the given expression evaluates 0, then 8 is exactly divisible by 2.

Step by step descriptive logic to check whether a number is divisible by 5 and 11 or not.

1. Input a number from user. Store it in some variable say num.
2. To check divisibility with 5, check if(num % 5 == 0) then num is divisible by 5.
3. To check divisibility with 11, check if(num % 11 == 0) then num is divisible by 11.
4. Now combine the above two conditions using logical AND operator &&. To check divisibility with 5 and 11 both, check if((num % 5 == 0) && (num % 11 == 0)), then number is divisible by both 5 and 11.

Let us implement the logic.

Program to check divisibility of a number

/**
 * C program to check divisibility of any number
 */

#include <stdio.h>

int main()
{
    int num;

    /* Input number from user */
    printf("Enter any number: ");
    scanf("%d", &num);


    /*
     * If  num modulo division 5 is 0 
     * and num modulo division 11 is 0 then
     * the number is divisible by 5 and 11 both
     */
    if((num % 5 == 0) && (num % 11 == 0))
    {
        printf("Number is divisible by 5 and 11");
    }
    else
    {
        printf("Number is not divisible by 5 and 11");
    }

    return 0;
}

Let us get little geeky and impress others. You can also write the above divisibility condition as

if(!(num % 5) && !(num % 11))
    printf("Number is divisible by 5 and 11");
else
    printf("Number is not divisible by 5 and 11");

Think how it works. Still in doubt give 2 minutes on logical NOT operator !.

Important note: Always remember modulo operator % does not work with float data type.

Enter any number: 55
Number is divisible by 5 and 11

Happy coding 😉