**Specification:**

Accept the principle amount, no of years, rate of interest and print the simple interest, the total amount must be paid to the financier.

Logic: si=p*n*r/100

#include<stdio.h> int main() { int p,n; float r,si,tot; printf("Principle Amount:"); scanf("%d",&p); printf("Number of years:"); scanf("%d",&n); printf("Rate of interest:"); scanf("%f",&r); si=p*n*r/100; tot=p+si; printf("Principle amount %d",p); printf("\nSimple interest %f",si); printf("\nTotal amount %f",tot); return 0; }

Execution:

Principle Amount:5200

Number of years:3

Rate of interest:8.5

Principle amount 5200

Simple interest 1326.000000

Total amount 6526.000000

Here I am going to introduce two functions pow() and sqrt() to calculate x to the power of y and square root of x. Add **#include<math.h>** to the program to use these functions.

#include<stdio.h> #include<math.h> int main() { double a=pow(4,5); double b=sqrt(81); printf("4 to the power of 5 is %.0lf",a); printf("\nSquare root of 81 is %.0lf",b); return 0; }

Output:

4 to the power of 5 is 1024

Square root of 81 is 9

**Specification:**

Accept the base and height of a triangle and print the area

Formula: ½ * b * h

#include<stdio.h> int main() { int b,h; float area; printf("Breadth:"); scanf("%d",&b); printf("Height:"); scanf("%d",&h); area=(float)1/2*b*h; printf("Area of triangle %f",area); return 0; }

Execution:

Breadth:12

Height:23

Area of triangle 138.000000

**Specification:**

Accept single side of equilateral triangle and print its area.

Logic: A triangle with sides of equivalent length is called equilateral triangle

Formula: √3/4 * (a^{2})

#include<stdio.h> #include<math.h> int main() { int a; float area; printf("Enter the length of any side:"); scanf("%d",&a); area=sqrt((float)3/4)*pow(a,2); printf("Area of triangle %f",area); return 0; }

Execution:

Enter the length of any side:15

Area of triangle 194.855713

**Specification:**

Accept three sides of a triangle and print its area.

Formula: √ s*(s-a)*(s-b)*(s-c) where s is (a+b+c)/2 [Heron’s formula]

#include<stdio.h> #include<math.h> int main() { int a,b,c; float s,area; printf("Enter three sides of a triangle:\n"); scanf("%d%d%d",&a,&b,&c); s=(a+b+c)/2.0; area=sqrt(s*(s-a)*(s-b)*(s-c)); printf("Area of triangle %f",area); return 0; }

Execution:

Enter three sides of a triangle:

9 12 7

Area of triangle 31.304953

**Specification:**

A cashier has currency notes of 10, 50 and 100. If the amount is input through the keyboard, print denomination of currency notes the cashier has to give.

#include<stdio.h> int main() { int amt; int hs=0,ffs=0,tns=0; printf("Enter the amount:"); scanf("%d",&amt); hs=amt/100;/* finding 100's in amount*/ amt=amt%100;/* removing 100's in amount*/ ffs=amt/50;/*finding 50's in amount*/ amt=amt%50;/*removing 50's in amount*/ tns=amt/10;/*finding 10's in amount*/ printf("Denomination:\n"); printf("100 x %d\n50 x %d\n10 x %d",hs,ffs,tns); return 0; }

Execution:

Enter the amount:5460

Denomination:

100 x 54

50 x 1

10 x 1

**Specification:**

Accept selling price of 20 items, total profit gained by the transactions and print the purchase price of each item.

Logic:

selling price – purchase price = profit

purchase price=selling price – profit

purchase price of each unit=purchase price/20 (no of units)

#include<stdio.h> int main() { float s_price,p_price,profit,unit_price; printf("Enter the selling price:"); scanf("%f",&s_price); printf("Enter the profit:"); scanf("%f",&profit); unit_price=(s_price-profit)/20; printf("Purchase cost of each unit %.2f",unit_price); return 0; }

Execution:

Enter the selling price:5000

Enter the profit:1000

Purchase cost of each unit 200.00

**Specification:**

The population of town is 50,000. The percentage of literacy in the town is 42%. If the percentage of literate man in the town is 34% then print the total number of literate man and women.

#include<stdio.h> int main() { long int population,no_literates,no_men_literates,no_wmen_literates; population=50000; no_literates=population*42/100; no_men_literates=population*34/100; no_wmen_literates=no_literates-no_men_literates; printf("Number of men literates %ld",no_men_literates); printf("\nNumber of women literates %ld",no_wmen_literates); return 0; }

Output:

Number of men literates 17000

Number of women literates 4000