30 Important C programming questions on the while loop


Q 1. Write a program to print numbers from 1 to 10 using a `while` loop.

Expected Output:

1 2 3 4 5 6 7 8 9 10

Q 2. Write a program to print even numbers between 1 and 20 using a `while` loop.

Expected Output:

2 4 6 8 10 12 14 16 18 20

Q 3. Write a program to find the sum of the first 10 natural numbers using a `while` loop.

Expected Output:

Sum = 55

Q 4. Write a program to reverse the digits of a given number using a `while` loop. For example, if the number is 12345, the output should be 54321.

Expected Output:

Enter a number: 12345

Reversed Number = 54321

Q 5. Write a program to count the number of digits in a given number using a `while` loop.

Expected Output:

Enter a number: 12345

Number of digits = 5

Q 6. Write a program to find the factorial of a given number using a `while` loop.

Expected Output:

Enter a number: 5

Factorial = 120

Q 7. Write a program to check if a given number is prime using a `while` loop.

Expected Output:

Enter a number: 7

7 is a prime number

Q 8. Write a program to print the multiplication table of a given number using a `while` loop.

Expected Output:

Enter a number: 5

5 x 1 = 5

5 x 2 = 10

5 x 3 = 15

...

5 x 10 = 50

Q 9. Write a program to find the GCD (Greatest Common Divisor) of two numbers using a `while` loop.

Expected Output:

Enter two numbers: 56 98

GCD = 14

Q 10. Write a program to calculate the sum of the digits of a given number using a `while` loop.

Expected Output:

Enter a number: 12345

Sum of digits = 15

Q 11. Write a program to calculate the power of a number using a `while` loop.

Expected Output:

Enter base and exponent: 2 3

2^3 = 8

Q 12. Write a program to find the LCM (Least Common Multiple) of two numbers using a `while` loop.

Expected Output:

Enter two numbers: 15 20

LCM = 60

Q 13. Write a program to print the Fibonacci series up to `n` terms using a `while` loop.

Expected Output:

Enter number of terms: 10

0 1 1 2 3 5 8 13 21 34

Q 14. Write a program to check if a given number is a palindrome using a `while` loop.

Expected Output:

Enter a number: 12321

12321 is a palindrome

Q 15. Write a program to find the sum of the first `n` natural numbers using a `while` loop.

Expected Output:

Enter a number: 10

Sum = 55

Q 16. Write a program to print all odd numbers between 1 and 50 using a `while` loop.

Expected Output:

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49

Q 17. Write a program to calculate the average of `n` numbers using a `while` loop.

Expected Output:

Enter the number of elements: 5

Enter 5 numbers: 10 20 30 40 50

Average = 30

Q 18. Write a program to find the sum of squares of the first `n` natural numbers using a `while` loop.

Expected Output:

Enter a number: 3

Sum of squares = 14

Q 19. Write a program to generate and print the first `n` prime numbers using a `while` loop.

Expected Output:

Enter the number of prime numbers: 5

2 3 5 7 11

Q 20. Write a program to print the following pattern using a `while` loop:

** 

***

**** 

*****

Q 21. Write a program to check if a given number is an Armstrong number using a `while` loop. (An Armstrong number is an integer such that the sum of the cubes of its digits is equal to the number itself.)

Expected Output:

Enter a number: 153

153 is an Armstrong number

Q 22. Write a program to find the sum of the first `n` terms of an arithmetic progression (AP) using a `while` loop. The first term and common difference should be provided by the user.

Expected Output:

Enter first term, common difference, and number of terms: 2 3 5

Sum = 40

Q 23. Write a program to check if a given number is a perfect number using a `while` loop. (A perfect number is a number that is equal to the sum of its divisors, excluding itself.)

Expected Output:

Enter a number: 6

6 is a perfect number

Q 24. Write a program to convert a given decimal number to binary using a `while` loop.

Expected Output:

Enter a decimal number: 10

Binary = 1010

Q 25. Write a program to calculate compound interest using a `while` loop. The formula for compound interest is `A=P(1+rn)nt`, where `P` is the principal amount, `r` is the annual interest rate, `n` is the number of times interest is compounded per year, and `t` is the number of years.

Expected Output:

Enter principal, rate, time, and number of times compounded: 1000 5 2 4

Compound Interest = 1104.94

Q 26. Write a program to print all prime numbers between 1 and 100 using a `while` loop.

Expected Output:

2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97

Q 27. Write a program to calculate the product of the digits of a given number using a `while` loop.

Expected Output:

Enter a number: 123

Product of digits = 6

Q 28. Write a program to print the first `n` multiples of a given number using a `while` loop.

Expected Output:

Enter a number: 3

Enter the number of multiples: 5

3 6 9 12 15

Q 29. Write a program to find the average of the digits in a given number using a `while` loop.

Expected Output:

Enter a number: 12345

Average of digits = 3.00

Q 30. Write a program to check if a given number is a strong number using a `while` loop. (A strong number is a number in which the sum of the factorial of its digits is equal to the number itself.)

Expected Output:

Enter a number: 145

145 is a strong number

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Bikki Singh

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