Level 1

1.

What would be the value of 'a':

a. int a = 10/45*23%45/(45%4*21)

b. float a = 10+45.0*23-45+(4*21.0)

2.

True or false (0 or not):

a. 4>5 && 5>4

b. 4>5 || 5>4

c. (232+23*1233) || 0

d. (232+23*1233) && 0

3.

If a is 15, then what would be the value of:

printf("%d",++a);

printf("%d",a++);

printf("%d",--a);

printf("%d",a--);

4.

What would be the output of:

printf("%d\n",1==5==5);

5.

What is the error in:

int a;

3=a

Level 2

1.

Length and breadth of a rectangle are 5 and 7 respectively. Write a program to calculate the area and perimeter of the rectangle.

Answer

```
#include <stdio.h>
main(){
int l = 5, b = 7;
int area, perimeter;
area = l*b;
perimeter = 2*(l + b);
printf("area: %d\n", area);
printf("perimeter: %d\n", perimeter);
}
```

2.

Write a program to input the value of the radius of a circle from keyboard and then calculate its perimeter and area.

Answer

```
#include <stdio.h>
main(){
int r, area, perimeter;
printf("Enter radius of circle\n");
scanf("%d", &r);
area = 3.14 * r * r;
perimeter = 2 * 3.14 * r;
printf("area: %d\n", area);
printf("perimeter: %d\n", perimeter);
}
```

3.

Write a program to enter a 4 digit number from keyboard. Add 8 to the number and then divide it by 3. Now, the modulus of that number is taken with 5 and then multiply the resultant value by 5. Display the final result.

Answer

```
#include <stdio.h>
main(){
int n;
printf("Enter a 4 digit number\n");
scanf("%d", &n);
float i;
i = (((n + 8)/3)%5)*5;
printf("%f\n", i);
}
```

4.

Now, solve the above question using assignment operators (eg. +=, -=, *=).

5.

Enter two numbers from keyboard. Write a program to check if the two numbers are equal.

Answer

```
#include <stdio.h>
main(){
int x, y;
scanf("%d %d", &x, &y);
printf("%d\n", (x == y)); //value of the expression (x == y) is 1 when true and 0 when false
}
```

6.

Write a program to enter the values of two variables 'a' and 'b' from keyboard and then check if both the conditions 'a < 50' and 'a < b' are true.

Answer

```
#include <stdio.h>
main(){
int a, b;
scanf("%d %d", &a, &b);
printf("%d\n", ((a < 50) && (a < b))); //value of the expression is 1 when both the conditions are true and 0 when atleast one of the conditions is false
}
```

7.

Now solve the above question to check if atleast one of the conditions 'a < 50' and 'a < b' is true.

Answer

```
#include <stdio.h>
main(){
int a, b;
scanf("%d %d", &a, &b);
printf("%d\n", ((a < 50) || (a < b))); //value of the expression is 1 when either of the conditions is true and 0 when both are false
}
```

8.

If the marks of Robert in three subjects are 78,45 and 62 respectively (each out of 100 ), write a program to calculate his total marks and percentage marks.

9.

Write a program to enter the values of two variables from the keyboard and then interchange the values of the two variables. E.g.-

If entered value of x is 5 and y is 10 then

**printf("%d %d",x,y )**

should print**10 5**.

If entered value of x is 5 and y is 10 then

should print

Answer

```
#include <stdio.h>
main(){
int x, y, temp;
printf("Enter the values of the numbers\n");
scanf("%d %d", &x, &y);
printf("Before interchanging\n x = %d\n y = %d\n", x, y);
temp = x; //temp is assigned the value of x
x = y; //x is assigned the value of y
y = temp; //y is assigned the value of temp i.e. the original value of x
printf("After interchanging\n x = %d\n y = %d\n", x, y);
}
```

10.

Take input of some length in meter and covert it to feet and inches.

11.

Write a program to convert Fahrenheit into Celsius.

12.

The total number of students in a class are 45 out of which 25 are boys. If 80% of the total students secured grade 'A' out of which 15 are boys, then write a program to calculate the total number of girls getting grade 'A'.

Answer

```
#include <stdio.h>
main(){
int total, b, g;
total = (80*45)/100; //total students getting grade A
b = 15; //number of boys getting grade A
g = total - b; //number of girls getting grade A
printf("number of girls getting grade A = %d\n", g);
/*note that we did not write 'total = (80/100)*45'*/
}
```

Level 3

1.

Write a program to calculate the sum of the first and the second last digit of a 5 digit number entered from the keyboard.

Answer

```
#include <stdio.h>
main(){
int n, first, second, third, forth, fifth, sum;
printf("Enter a 5-digit number\n");
scanf("%d", &n);
/*Now we will take out each digit of this number and then finally add the first and the second last digits*/
first = n/10000; //first digit
n = n%10000;
second = n/1000; //second digit
n = n%1000;
third = n/100; //third digit
n = n%100;
forth = n/10; //forth digit
fifth = n%10; //fifth digit
sum = first + forth;
printf("sum : %d\n", sum);
}
```

2.

Suppose you entered a 4 digit number. Write a program to display a number whose digits are 2 greater than the corresponding digits of the entered number.

For example, if he entered number is 5696, then the displayed number should be 7818.

For example, if he entered number is 5696, then the displayed number should be 7818.

3.

Write a program to calculate the sum of the digits of a 3-digit number which is entered from keyboard. E.g.-

INPUT : 132 OUTPUT : 6

INPUT : 132 OUTPUT : 6

Answer

```
#include <stdio.h>
main(){
int n, first, second, third, sum;
printf("Enter a 3-digit number\n");
scanf("%d", &n);
first = n/100; //first digit
n = n%100;
second = n/10; //second digit
third = n%10; //third digit
sum = first + second + third;
printf("sum : %d\n", sum);
}
```

4.

Write a program to reverse a 3-digit number which is entered from keyboard. E.g.-

INPUT : 132 OUTPUT : 231

INPUT : 132 OUTPUT : 231

Answer

```
#include <stdio.h>
main(){
int n, first, second, third, reverse;
printf("Enter a 3-digit number\n");
scanf("%d", &n);
/*finding the digits of the entered number n*/
first = n/100; //first digit
n = n%100;
second = n/10; //second digit
third = n%10; //third digit
/*reverse number */
reverse = third*100 + second*10 + first;
printf("reverse number : %d\n", reverse);
}
```

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