grade point generetor

#include <stdio.h>

int main()
{
    float a;
    printf("enter your marks:");
    scanf("%f",&a);
    if(a>=80&&a<=100)
    {
        printf("CONGRATULATIONS! you got A+\n");
        printf("4.00\n");
    }

    if (a>=75&&a<=79)
    {
        printf("A\n");
        printf("3.75\n");
    }

    if (a>=70&&a<=74)
    {
        printf("A-\n");
        printf("3.50\n");
    }

    if (a>=65&&a<=69)
    {
       printf("B+\n");
        printf("3.25\n");
    }

    if (a>=60&&a<=64)
    {
      printf("B\n");
        printf("3.00\n");
    }

    if (a>=55&&a<=59)
    {
       printf("B-\n");
        printf("2.75\n");
    }

    if (a>=50&&a<=54)
    {
       printf("C+\n");
        printf("2.50\n");
    }

    if (a>=45&&a<=49)
    {
        printf("C\n");
        printf("2.25\n");
    }

    if (a>=40&&a<=44)
    {
       printf("D\n");
        printf("2.00\n");
    }

    if (a>=00&&a<=39)
    {
      printf("F\n");
        printf("0.00\n");
    }


 return 0;
}