solution

#include<iostream.h>
#include<conio.h>

int main()
{
 float basic_salary, gross_salary, HRA, DA;
 cout<<"Enter basic salary of Employee : ";
 cin>>basic_salary;

 if (basic_salary<1500)
 {
  HRA=0.1*basic_salary;
  DA=0.9*basic_salary;
 }
 else
 { 
  HRA=500;
  DA=0.98*basic_salary;
 }

 gross_salary=basic_salary+HRA+DA;
 cout<<"Gross salary is : "<<gross_salary;

 getch();
 return 0;
}