C Exercises: Read five subject marks (0-100) of a student and calculate the average

Last update on September 19 2025 12:45:10 (UTC/GMT +8 hours)

Calculate the average of marks from 5 subjects

Write a C program that reads five subject marks (0-100) of a student and calculates the average of these marks.

Sample Solution:

C Code:

#include <stdio.h>

int main () {
    float marks, tot_marks = 0;
    int i = 0, subject = 0;

    // Prompt user for input
    printf("Input five subject marks(0-100):\n");

    // Loop to read marks for five subjects
    while (subject != 5) {

        // Read a float value 'marks' from user
        scanf("%f", &marks);

        // Check if 'marks' is within valid range (0-100)
        if (marks < 0 || marks > 100) {
            printf("Not a valid marks\n"); // Print an error message
        }
        else {
            tot_marks += marks; // Accumulate valid marks
            subject++; // Increment subject count
        }
    }

    // Calculate and print the average marks
    printf("Average marks = %.2f\n", tot_marks/5);

    return 0; // End of program
}

Sample Output:

Input five subject marks(0-100):
75
84
56
98
68
Average marks = 76.20

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C program to read five subject marks, validate each input, and compute the average with two decimal precision.
• Write a C program to calculate the average marks using an array and a loop, ensuring values are between 0 and 100.
• Write a C program to implement a function that computes the average of five marks and prints a grade based on the result.
• Write a C program to compute the average of marks, and then display a message if the student passes or fails based on a threshold.

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