Write a program in C for grade calculation using if…else if ladder and switch Statement. Accept marks of 3 subjects calculate total and based on it calculate Grade.

FLOWCHART

Start

Input marks for 3 subjects (sub1, sub2, sub3)

Calculate Total Marks (total = sub1 + sub2 + sub3)

Calculate Average Marks (average = total / 3)

Check if all subjects have marks >= 33 (to pass)

• If YES, proceed to calculate the grade.
• If NO, print "FAILED" and stop.

Check the grade based on the average using if-else conditions:

• If average >= 80, assign grade 'A'.
• Else if average >= 65, assign grade 'B'.
• Else if average >= 45, assign grade 'C'.
• Else if average >= 33, assign grade 'D'.
• Else assign grade 'F' (failed).

Display total marks, average, and grade.

End


#include <stdio.h>

int main() {
    int sub1, sub2, sub3, total;
    float average;
    char grade;
    
    // Input marks for 3 subjects
    printf("Enter marks of 1st Subject: ");
    scanf("%d", &sub1);
    
    printf("\nEnter marks of 2nd Subject: ");
    scanf("%d", &sub2);
    
    printf("\nEnter marks of 3rd Subject: ");
    scanf("%d", &sub3);
    
    // Total Marks and Average
    total = sub1 + sub2 + sub3;
    average = total / 3.0;
    
    // Check if passed
    if (sub1 >= 33 && sub2 >= 33 && sub3 >= 33) {
        printf("\nTotal Marks: %d", total);
        printf("\nAverage Marks: %.2f", average);
        
        // Grade calculation using if...else if ladder
        if (average >= 80) {
            grade = 'A';
        } else if (average >= 65) {
            grade = 'B';
        } else if (average >= 45) {
            grade = 'C';
        } else if (average >= 33) {
            grade = 'D';
        } else {
            grade = 'F'; // F for fail if below 33
        }
        
        // Display grade using switch statement
        switch(grade) {
            case 'A':
                printf("\nStudent has A grade.");
                break;
            case 'B':
                printf("\nStudent has B grade.");
                break;
            case 'C':
                printf("\nStudent has C grade.");
                break;
            case 'D':
                printf("\nStudent has D grade.");
                break;
            case 'F':
                printf("\nStudent has FAILED, advised to re-take exam.");
                break;
            default:
                printf("\nInvalid grade.");
        }
    } else {
        printf("\nStudent has FAILED, advised to re-take exam.");
    }

    return 0;
}