Maths Quiz Problem

#include <stdio.h>
main()
{
    int opt; //Menu options
    int numof; //Number of questions
    int ans; //Answers

    opt=0;

    numof=0;

    ans=0;



    printf("\n________________________________________________________________________________________________________");
    printf("Select an option displayed below________________________");
    printf("________________________________________________________________________________\n\n\n");
    printf("1: Enter the number of questions to be asked for this round of the quiz (maximum of 5 questions allowed).\n\n");
    printf("2: Start quiz\n\n");
    printf("3: Display the number of questions that were answered (i) correctly and (ii) incorrectly for this round.\n\n");
    printf("4: Exit Program\n");
    printf("________________________________________________________________________________\n\n");

    scanf("%d", &opt);


    if(opt==1)
    {
        if(numof==1)
        {
            printf("Let's begin\n");
            printf("12x4=?\n");

            scanf("%d", &ans);


            if(ans==48)
            {
                printf("Success! You are correct");
            }
            else
            {
                printf("Uh oh, you were wrong. Hard luck.");
            }//End inner if 1
        }//End middle if 1





        if(numof==2)
        {
            printf("Let's begin\n");
            printf("12x4=?\n");

            scanf("%d", &ans);

            if(ans==48)
            {
                printf("Success! You are correct\n\n");
                printf("102/2=?\n");

                scanf("%d", &ans);


                if(ans==51)
                {
                    printf("Success! You are correct\n");
                }
                else
                {
                    printf("Uh oh, you were wrong. Hard luck.");
                }//End inner if 2b
            }
            else
            {
                printf("Uh oh, you were wrong. Hard luck.");
            }//End inner if 2a
        }//End middle if 2






        if(numof==3)
        {
            printf("Let's begin\n");
            printf("12x4=?\n");

            scanf("%d", &ans);

            if(ans==48)
            {
                printf("Success! You are correct\n\n");
                printf("102/2=?\n");

                scanf("%d", &ans);


                if(ans==51)
                {
                    printf("Success! You are correct\n\n");
                    printf("10/2*3=?\n");

                    scanf("%d", &ans);


                    if(ans==15)
                    {
                        printf("Success! You are correct\n\n");
                    }
                    else
                    {
                        printf("Uh oh, you were wrong. Hard luck.");
                    }//End innner if 3c
                }
                else
                {
                    printf("Uh oh, you were wrong. Hard luck.");
                }//End inner if 3b
            }
            else
            {
                printf("Uh oh, you were wrong. Hard luck.");
            }//End inner if 3a
        }//End middle if 3




        if(numof==4)
        {
            printf("Let's begin\n");
            printf("12x4=?\n");

            scanf("%d", &ans);

            if(ans==48)
            {
                printf("Success! You are correct\n\n");
                printf("102/2=?\n");

                scanf("%d", &ans);


                if(ans==51)
                {
                    printf("Success! You are correct\n\n");
                    printf("10/2*3=?\n");

                    scanf("%d", &ans);


                    if(ans==15)
                    {
                        printf("Success! You are correct\n\n");
                        printf("40*2/4=?\n");

                        scanf("%d", &ans);


                        if(ans==20)
                        {
                            printf("Success! You are correct\n\n");
                        }
                        else
                        {
                            printf("Uh oh, you were wrong. Hard luck.");
                        }//End inner if 4d
                    }
                    else
                    {
                        printf("Uh oh, you were wrong. Hard luck.");
                    }//End innner if 4c
                }
                else
                {
                    printf("Uh oh, you were wrong. Hard luck.");
                }//End inner if 4b
            }
            else
            {
                printf("Uh oh, you were wrong. Hard luck.");
            }//End inner if 4a
        }//End middle if 4




        if(numof==5)
        {
            printf("Let's begin\n");
            printf("12x4=?\n");

            scanf("%d", &ans);


            if(ans==48)
            {
                printf("Success! You are correct\n\n");
                printf("102/2=?\n");

                scanf("%d", &ans);


                if(ans==51)
                {
                    printf("Success! You are correct\n\n");
                    printf("10/2*3=?\n");

                    scanf("%d", &ans);


                    if(ans==15)
                    {
                        printf("Success! You are correct\n\n");
                        printf("40*2/4=?\n");

                        scanf("%d", &ans);


                        if(ans==20)
                        {
                            printf("Success! You are correct\n\n");
                            printf("75/3*5=?");

                            scanf("%d", &ans);


                            if(ans==125)
                            {
                                printf("Success! You are correct\n\n");
                            }
                            else
                            {
                                printf("Uh oh, you were wrong. Hard luck.\n\n");
                            }//End inner 5e
                        }
                        else
                        {
                            printf("Uh oh, you were wrong. Hard luck.\n\n");
                        }//End inner if 5d
                    }
                    else
                    {
                        printf("Uh oh, you were wrong. Hard luck.\n\n");
                    }//End innner if 5c
                }
                else
                {
                    printf("Uh oh, you were wrong. Hard luck.\n\n");
                }//End inner if 5b
            }
            else
            {
                printf("Uh oh, you were wrong. Hard luck.\n\n");
            }//End inner if 5a
        }//End middle if 5


    }//End main if

    flushall();
    getchar();


}//End main()