C Assignment (Electricity bill) Remodified

/* WAP to calculate the electricity bill */
#include
#include
void main()
{
int a,b,c,d,e,f,g;
clrscr();
printf("enter your value in Units: ");
scanf("%d",&a);
if(0<=a&&a<=100)
{
b=a*2;
printf("\nYour Bill is Rs.%d for %d Units. \n\n\tTotal = Rs.%d",b,a,b);
}
else if(101<=a&&a<=200)
{
b=a-100;
c=100*2;
d=b*3;
e=c+d;
printf("\nYour Bill is Rs.%d for first 100 Units. \n\tRs.%d for %d Units. \n\n\tTotal = Rs.%d",c,d,b,e);
}
else if(201<=a&&a<=300)
{
b=a-200;
c=100*2;
d=100*3;
e=b*4;
f=c+d+e;
printf("\nYour Bill is Rs.%d for first 100 Units. \n\tRs.%d for second 100 Units. \n\tRs.%d for %d Units. \n\n\tTotal = Rs.%d",c,d,e,b,f);
}
else if(a>300)
{
b=a-300;
c=100*2;
d=100*3;
e=100*4;
f=b*5;
g=c+d+e+f;
printf("\nYour Bill is Rs.%d for first 100 Units. \n\tRs.%d for second 100 Units. \n\tRs.%d for third 100 Units. \n\tRs.%d for %d Units afterwards. \n\n\tTotal = Rs.%d",c,d,e,f,b,g);
}
else
{
printf("\nEnter Value in Numbers Only");
}
getch();
}