11. Write a C program to find the gross salary of an employee Gross salary = base salary + DA + HRA+Bonus DA= 40 % of the base salary, HRA=80% of DA, and Bonus= 25% of HRA. Ask user to enter the base salary only.

#include<stdio.h>
int main()
{
int bs,da,hra,gs,bonus;
printf("Enetr Base Salary");
scanf("%d",&bs);
da=(40*bs)/100;
hra=(80*da)/100;
bonus=(25*hra)/200;
gs=da+hra+bonus+bs;
printf("%d",gs);
return 0;
}

10. Write a C program to convert a given number of days into months and days.

#include<stdio.h>
int main()
{
int d;
printf("Enter days\n");
scanf("%d",&d);
printf("%d years,%d months,%d days\n",d/365,(d%365)/30,(d%365)%30);
	return 0;
}

9. Write a C program to determine the amount of compound interest to be paid by the borrower, if the principal amount, rate of interest, and tenure are entered by the user.

#include<stdio.h>
#include<math.h>
int main()
{
 float p,rate,time,ci;
 printf("Enter principal amount : ");
 scanf("%f", &p);
 printf("Enter interest rate : ");
 scanf("%f", &rate);
 printf("Enter time period in year : ");
 scanf("%f", &time);
 ci=p*(pow((1+rate/100),time)-1);
 printf("\nCompound interest = %f",ci);
 return 0;
}

8. Write a C program to determine the amount of interest to be paid by the borrower, if the principal amount, rate of interest, and tenure are entered by the user.

#include<stdio.h>
int main( )
{
	float p,rate,n,si;
	printf("Enter principal amount : ");
 scanf("%f", &p);
 printf("Enter interest rate : ");
 scanf("%f", &rate);
 printf("Enter time period in year : ");
 scanf("%f", &n);
	si = p * n * rate / 100 ;
	printf("\nSimple interest = %f",si);
	return 0;
}

6 & 7)Write a C program to determine the amount of profit or loss (in percentage) a seller has made, if the cost price and selling price of an article are entered by the user.

#include<stdio.h>
int main()
{
	float cp,sp,pro=0,loss=0,lossper,proper;
	printf("Enter sp and cp");
	scanf("%f%f",&sp,&cp);
	if(cp>sp)
	{
		loss=cp-sp;
				}
	else if(sp>cp)
	{
		pro=sp-cp;
	}
	lossper=(loss/cp)*100;
	proper=(pro/cp)*100;
	if(cp>sp)
	{
		printf("Loss Percentage is %f",lossper);
	}
	else if(sp>cp)
	{
		printf("Profit Percentage is %f",proper);
	}
	return 0;

}

5. Write a C program to print the sum of the cube of n natural numbers. the sum of cubes of first ‘n’ natural no`s- 1^3+2^3+3^3+4^3+……+n^3=(n^2 * (n+1)^2)/4

#include<stdio.h>
int main()
{
int n,sum=0;
printf("Enter Number");
scanf("%d",&n);
sum=(n*n*(n+1)*(n+1))/4;
printf("%d",sum);
return 0;
}

4. Write a C program to print the sum of the square of n natural numbers. the sum of squares of first ‘n’ natural no`s- 1^2+2^2+3^2+…..+n^2=n*(n+1)*(2n+1)/6

#include<stdio.h>
int main()
{
int n,sum=0;
printf("Enter Number");
scanf("%d",&n);
sum=n*(n+1)*(2*n+1)/6 ;
printf("%d",sum);
return 0;
}

3.Write a C program to print the sum of n natural numbers. the sum of first ‘n’ natural no`s- 1+2+3+…..+n=n*(n+1)/2

#include<stdio.h>
int main()
{
int n,sum=0;
printf("Enter Number");
scanf("%d",&n);
sum=n*(n+1)/2;
printf("%d",sum);
return 0;
}