Write a C program to count the number of students belonging to each of following groups of marks

    int marks[] = {43,65,51,27,79,11,56,61,82,9,25,36,7,49,55,63,74,81,49,37,40,49,16,75,87,91,33,24,58,78,65,56,76,67,45,54,36,63,12,21,73,49,51,19,39,49,68,93,85,58};
    int marksRangesCount[]={0,0,0,0,0,0,0,0,0,0};
    //printf("%d\n",(int)sizeof(marks));
    for(int i=0;i<50;i++)
    {
        if(marks[i]>=0 && marks[i]<=9)
        marksRangesCount[0]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
        else if(marks[i]>=10 && marks[i]<=19)
        marksRangesCount[1]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
        else if(marks[i]>=20 && marks[i]<=29)
        marksRangesCount[2]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
        else if(marks[i]>=30 && marks[i]<=39)
        marksRangesCount[3]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
        else if(marks[i]>=40 && marks[i]<=49)
        marksRangesCount[4]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
        else if(marks[i]>=50 && marks[i]<=59)
        marksRangesCount[5]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
        else if(marks[i]>=60 && marks[i]<=69)
        marksRangesCount[6]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
        else if(marks[i]>=70 && marks[i]<=79)
        marksRangesCount[7]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
        else if(marks[i]>=80 && marks[i]<=89)
        marksRangesCount[8]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
        else if(marks[i]>90 && marks[i]<=100)
        marksRangesCount[9]++; //same like : marksRangesCount[0]=marksRangesCount[0]+1; 
         
        //printf("%d\n",marks[i]);
    }
    printf("Count of marks ranges:\n-----------------------------\n");
    printf("0 to 9 : %d\n",marksRangesCount[0]);
    printf("10 to 19 : %d\n",marksRangesCount[1]);
    printf("20 to 29 : %d\n",marksRangesCount[2]);
    printf("30 to 39 : %d\n",marksRangesCount[3]);
    printf("40 to 49 : %d\n",marksRangesCount[4]);
    printf("50 to 59 : %d\n",marksRangesCount[5]);
    printf("60 to 69 : %d\n",marksRangesCount[6]);
    printf("70 to 79 : %d\n",marksRangesCount[7]);
    printf("80 to 89 : %d\n",marksRangesCount[8]);
    printf("90 to 100 : %d\n",marksRangesCount[9]);

output:

Count of marks ranges:                                                                                                                          
-----------------------------                                                                                                                   
0 to 9 : 2                                                                                                                                      
10 to 19 : 4                                                                                                                                    
20 to 29 : 4                                                                                                                                    
30 to 39 : 5                                                                                                                                    
40 to 49 : 8                                                                                                                                    
50 to 59 : 8                                                                                                                                    
60 to 69 : 7                                                                                                                                    
70 to 79 : 6                                                                                                                                    
80 to 89 : 4                                                                                                                                    
90 to 100 : 2