01 #include<stdio.h>
02 
03 int main()
04 {
05     int marks;
06     printf("Enter Marks to know your GRADE : ");
07     scanf("%d",&marks);
08     if(marks<35)
09     {
10         printf("Grade 'F'");
11     }
12     else if(marks>=35 && marks<=40)
13     {
14         printf("Grade 'D'");
15     }
16     else if(marks>=41 && marks<50)
17     {
18         printf("Grade 'C'");
19     }
20     else if(marks>=50 && marks<60)
21     {
22         printf("Grade 'B'");
23     }
24     else if(marks>=60 && marks<70)
25     {
26         printf("Grade 'B+'");
27     }
28     else if(marks>=70 && marks<80)
29     {
30         printf("Grade 'A'");
31     }
32     else  // marks>80
33     {
34         printf("Grade 'A+'");
35     }
36     return 0;
37 }

 OUTPUT :
 
 Enter Marks to know your GRADE : 78
 Grade 'A'