## Question 1

Please input an integer number. (output)

3 (or 4) ⏎ (input)

3 (or 4) is an odd (or even) number . (output)

#include<stdio.h>

int main (void) {
int input;
int i;

printf("Please input an integer.\n");
scanf("%d", &input);

if (input % 2 == 0) {
printf("%d is an even number\n", input);
} else {
printf("%d is an odd number\n", input);
}

return 0;
}

## Question 2

Please input your height (cm) and weight (kg). (output)

172.3 ⏎ (input)

65.0 ⏎ (input)

Your BMI is 21.890. (output)

The standard BMI is assumed to be 24.0. (output)

I’m afraid you are overweight (or underweight). (output)

#include<stdio.h>

int main (void) {
double height, weight, BMI;
double height_meter;

printf("Please input your height (cm) and weight (kg).\n");
scanf("%lf", &height);
scanf("%lf", &weight);

height_meter = height / 100.0;

BMI = (weight) / (height_meter * height_meter);

printf("Your BMI is %.2lf.\n", BMI);
printf("The standard BMI is assumed to be 24.0.\n");

if (BMI > 24.0) {
printf("I’m afraid you are overweight.\n");
} else {
printf("I’m afraid you are underweight.\n");
}

return 0;
}

## Question 3

Please input an integer number (> 1). (output)

7 ⏎ (input)

7 is a prime number. (output)

Please input an integer number (> 1). (output)

15 ⏎ (input)

15 is not a prime number. (output)

#include<stdio.h>

int main (void) {
int input;
int i;

printf("Please input an integer number (> 1).\n");
scanf("%d", &input);

for (i=2; i<=input; i++){
if (input % i == 0 && input != i) {
printf("%d is not a prime number.\n", input);
break;
}//end if
}//end for

if (i == input+1){
printf("%d is a prime number.\n", input);
}//end if
return 0;
}