C Program to Check if a Number is Divisible by 3 and 5

In this article, we will write a C program to check if a number is divisible by 3 and 5 both.

The program takes a number from the user as input and checks if it is divisible by 3 and 5 both.

Sample Input:

Enter a number: 15

Output:

Number is divisible by 3 and 5

A number is said to be perfectly divisible by another number if it can be divided by that number without leaving a remainder i.e. the remainder is 0.

In C programming language, we use the modulo operator(%) to get the remainder of a division operation. The modulo operator(%) takes two operands and returns the remainder by dividing the first number by the second eg. a%b.

For example, 9%3 will give us 0 as 9 is perfectly divisible by 3. We will use this concept to write our program.

The following C program shows how you can check if a number is divisible by 3 and 5 both:

// C program to check if a number is divisible by 3 and 5
#include <stdio.h>

int main() {

    int num;

    printf("Enter a number: ");
    scanf("%d", &num);

    // Check if number is divisible by 3 and 5 both
    if ((num % 3 == 0) && (num % 5 == 0)) {
        printf("Number is divisible by 3 and 5");
    } else {
        printf("Number is not divisible by 3 and 5");
    }

    return 0;

}

Output:

Enter a number: 15
Number is divisible by 3 and 5

Code Explanation:

• The program takes a number from the user and stores it in the num variable.
• Inside the if condition, the statement num % 3 == 0 evaluates to true only if the number is perfectly divisible by 3.
• Similarly, num % 5 == 0 evaluates to true only if the number is perfectly divisible by 5.
• If both statements evaluate to true, the code inside the if block runs and prints that the number is divisible by 3 and 5 both.
• If any of the two statements evaluate to false, the code inside the else block runs.

Thanks for reading.