The document contains 20 C programs that demonstrate various programming concepts like: 1. Taking input from the user and displaying output 2. Calculating the average, area, power of a number 3. Checking if a number is even/odd, positive/negative 4. Comparing numbers and displaying the largest/smallest 5. Conditional statements like if-else to classify ages, exam scores, leap years The student requests the teacher to solve the remaining programs in class for learning.

1. Md. Najmul Hassan
ID: 171-15-1399
Sec: PC-G

2. Declare a variable named num and assign the
value 100 to this variable. Display “The value is
100”
int main()
{
int num;
num = 100;
printf("The value is %dn", num);
return 0;
}

3. Write a C program that will take an integer, a float
and a character from keyboard and also display
these inputs.
#include <stdio.h>
int main()
{
int a;
float b;
char ch;
printf("Enter the Character:....n");
scanf("%c", &ch);
printf("Enter the Integer:....n");
scanf("%d", &a);
printf("Enter the float:....n");
scanf("%llf", &b);
printf("nCharacter = %cn", ch);
printf("Integer = %dn", a);
printf("Float = %llfn", b);
}

4. Write a C program that will take two numbers
and display the Average of these numbers
#include <stdio.h>
int main()
{
double a, b, ave;
printf("Enter the two numbers for find their average:....n");
scanf("%lf %lf", &a, &b);
ave = ((a+b)/2.0);
printf("Average is %.1lfn", ave);
return 0;
}

5. Write a C program to convert Celsius to
Fahrenheit. [Formula is: F= (9C/5) + 32].
#include <stdio.h>
int main()
{
float celsius, fahrenheit;
printf("Enter temperature in Celsius: ");
scanf("%f", &celsius);
fahrenheit = ((celsius * 9)/5) + 32;
printf("n%.2f Celsius = %.2f Fahrenheit", celsius, fahrenheit);
return 0;
}

6. Write a program that will display the area of a
rectangle. Take two inputs for length and width of
the rectangle from the keyboard.
#include <stdio.h>
int main()
{
double a, b, c;
printf("Enter the length and width:...n");
scanf("%lf %lf", &a, &b);
c = a*b;
printf("The rectangle is %.1lfn", c);
return 0;
}

7. Write a program that will display the area of a
Triangle. Take two inputs for base and height of
the Triangle from the keyboard
#include <stdio.h>
int main()
{
double a, b, c;
printf("Enter the base and height for find the area of triangle:......n");
scanf("%lf %lf", &a, &b);
c = 0.5 * a * b;
printf("The area of triangle is %.lfn", c);
return 0;
}

8. Write a program that computes the number
of seconds in a year
#include <stdio.h>
int main()
{
int a, b;
printf("Enter the number:....n");
scanf("%d", &a);
b = a / 365;
printf("%d yearn", b);
return 0;
}

9. Swapping of two numbers using C
#include <stdio.h>
int main()
{
int a, b, c=0;
printf("Enter two number:....n");
scanf("%d %d", &a, &b);
c=a;
a=b;
b=c;
printf("The numbers are %d and %dn", a, b);
return 0;
}

10. Write a C program that will take two numbers, first
one for a number, second one for the power and
display the power value of that number.
#include <stdio.h>
int main()
{
int base, power;
long long total = 1;
int i;
printf("Enter base: ");
scanf("%d", &base);
printf("Enter power: ");
scanf("%d", &power);
for(i=1; i<=power; i++)
{
total = total * base;
}
printf("n%d ^ %d = %lld", base, power,
total);
return 0;
}

11. Write a C program that will take a number and
displays the square root of number.
#include <stdio.h>
#include <math.h>
int main()
{
double num, result;
printf("Enter the number:....n");
scanf("%lf", &num);
result = sqrt(num);
printf("%lf number square root is %.1lfn", num, result);
return 0;
}

12. Write a C program that displays from 1 to
100.
#include <stdio.h>
int main()
{
int i;
for(i=1; i<=100; i++)
{
printf("%d, ", i);
}
return 0;
}

13. Write a C program that displays from 100 to 1.
#include <stdio.h>
int main()
{
int i;
for(i=100; i>=1; i--)
{
printf("%d ,", i);
}
return 0;
}

14. Write a C program that displays the even/odd
number from 1 to 100.
#include <stdio.h>
int main()
{
int odd, even, i;
for(i=100; i>=1; i--)
{
if(i%2==0)
{
printf("%d is a even numbern", i);
}
else
{
printf("%d is a odd numbern", i);
}
}
return 0;
}

15. Write a C program that will take an integer
number and display it “EVEN” or “ODD”.
#include <stdio.h>
int main()
{
int num, even, odd;
printf("Enter the number:...n");
scanf("%d", &num);
if(num % 2 ==0 )
{
printf("%d number is a even
numbern", num);
}
else
{
printf("%d number is a odd numbern",
num);
}
return 0;
}

16. Write a C program that will take a year. If its leap
year then display “YES” or otherwise “NO”.
#include <stdio.h>
int main()
{
int year;
printf("Enter year : ");
scanf("%d", &year);
if(((year%4 == 0) && (year%100 !=0))
|| (year%400==0))
{
printf("YESn");
}
else
{
printf("NOn");
}
return 0;
}

17. Write a C program that will take an integer
number and display “POSITIVE” or “NEGATIVE".
#include <stdio.h>
int main()
{
int num;
printf("Enter the number:....n");
scanf("%d", &num);
if(num>0)
{
printf("POSITIVEn");
}
else
{
printf("NEGATIVEn");
}
return 0;
}

18. Write a C program that will take three integer
numbers and display the small number.
#include <stdio.h>
int main()
{
int a, b, c;
printf("Enter the numbers:.....n");
scanf("%d %d %d", &a, &b, &c);
if(a<b)
{
if(a<c)
{
printf("%d is the small numbern", a);
}
else
{
printf("%d is the small numbern", c);
}
}
else if(b<a)
{
if(b<c)
{
printf("%d is the small numbern", b);
}
else
{
printf("%d is the small numbern", c);
}
}
return 0;
}

19. Write a C program that will take three integer
numbers and display the middle number
#include <stdio.h>
int main()
{
int a, b, c;
printf("Enter the numbers:....n");
scanf("%d %d %d", &a, &b, &c);
if(a>b)
{
if(a<c)
{
printf("%d is the middle
numbern", a);
}
else
{
printf("%d is the middle
numbern", c);
}
}
else if(b>a)
{
if(b<c)
{
printf("%d is the middle
numbern", b);
}
else
{
printf("%d is the middle
numbern", c);
}
}
return 0;
}

20. Write a C program that will take three integer
numbers and display the large number.
#include <stdio.h>
int main()
{
int a, b, c;
printf("Enter the numbers:....n");
scanf("%d %d %d", &a, &b, &c);
if(a>b)
{
if(a>c)
{
printf("%d is the large numbern",
a);
}
else
{
printf("%d is the large numbern",
c);
}
}
else if(b>a)
{
if(b>c)
{
printf("%d is the large numbern",
b);
}
else
{
printf("%d is the large numbern",
c);
}
}
return 0;
}

21. Write a C program that will take an age and if age less than 10 then display Minor. If
the age between 11 to 19 then display “Teen”, If the age between 20 to 39 then
display “Young”, If the age between 40 to 49 then display “Adult” otherwise “Old”.
#include <stdio.h>
int main()
{
int a;
printf("Enter the
age:.....n");
scanf("%d", &a);
if(a<10)
{
printf("Minorn");
}
else if(a>=11 && a<=19)
{
printf("Teenn");
}
else if(a>=20 && a<=39)
{
printf("Youngn");
}
else if(a>=40 && a<=49)
{
printf("Adultn");
}
else
{
printf("Oldn");
}
return 0;
}

22. Write a C program that will take a number and if the number is less than 40 then display “Fail”. If the
number is between 40 to 49 then display “D”, if the number is between 50 to 59 then display “C”. If
the number is between 60 to 69 then display “B”, if the number is between 70 to 79 then display “A”,
if the number is between 80 to 100 then display “A+”
#include <stdio.h>
int main()
{
int a;
printf("Enter the
numbern");
scanf("%d", &a);
if(a>=40 && a<=49)
{
printf("Dn");
}
else if(a>=50 && a<=59)
{
printf("Cn");
}
else if(a>=60 && a<=69)
{
printf("Bn");
}
else if(a>=70 && a<=79)
{
printf("An");
}
else if(a>=80 && a<=100)
{
printf("A+n");
}
else{
printf("Failn");
}
return 0;
}

23. Thank You
Sir I am sorry that I couldn’t able to do rest the C
program. If you can solve those in our class it will
be great help to us.