C Assignment (Electricity bill) Shorter

/* WAP to calculate the electricity bill */
#include
#include
void main()
{
int a,b,c;
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.",b,a);
}
else if(101<=a&&a<=200)
{
b=a-100;
c=100*2+b*3;
printf("\nYour Bill is Rs.%d for %d Units.",c,a);
}
else if(201<=a&&a<=300)
{
b=a-200;
c=100*2+100*3+b*4;
printf("\nYour Bill is Rs.%d for %d Units.",c,a);
}
else if(a>300)
{
b=a-300;
c=100*2+100*3+100*4+b*5;
printf("\nYour Bill is Rs.%d for %d Units.",c,a);
}
else
{
printf("\nEnter Value in Numbers Only");
}
getch();
}