text: /* a program to displaying grade based on marks*/
  #include<stdio.h>
  int main()
  {
      int marks,i;
      printf("\n enter the marks\n");
      scanf("%d",&marks);
      i=marks/10;
      switch(i)
      {
      case 10:
      case 9:
          printf("your grade is O");
          break;
      case 8:
          printf("your grade is E");
          break;
      case 7:
          printf("your grade is A");
          break;
      case 6:
          printf("your grade is B");
          break;
      case 5:
          printf("your grade is C");
          break;
      case 4:
          printf("your grade is D");
          break;
      case 3:
      case 2:
      case 1:
      case 0:
          printf("fail");
      default:
          printf("invalid range");
          break;
      }
      return 0;
  }
  