A long-distance carrier charges the following rates for telephone calls:

Starting time of call	Rate per minute
00:00-06:59	0.12
07:00-19:00	0.55
19.01-23.59	0.35

Write a program that asks for the starting time and the number of minutes of the call, and displays the charges. The program should ask for the time to be entered as a floating point number in the form HH.MM. For example, 07:00 hours will be entered as 07.00, and 16:28 hours will be entered as 16.28.

Input Validation: The program should not accept times that are greater than 23:59. Also, no number whose last two digits are greater than S 9 should be accepted. Hint: Assuming nunt is a floating-point variable, the following expression will give you its fractional part:

num - static_cast<int>(num)

When traveling through a gas, the speed of sound depends primarily on the density of the medium. The less dense the medium, the faster the speed will be. The following table shows the approximate speed of sound at 0 degree celsius, measured in meters per second, when traveling through carbon dioxide, air, helium, and hydrogen.

Write a program that displays a menu allowing the user to select one of these 4 gases. After a selection has been made, the user should enter the number of seconds it took for the sound to travel in this medium from its source to the location at which it was detected. The program should then report how far away (in meters) the source of the sound was from the detection location.

Input Validation: Check that the user has selected one of the available menu choices. Do not accept times less than 0 seconds or more than 30 seconds.

______ primarily depends on the intensity of sound .

The speed of sound varies depending on the medium through which it travels. In general, sound travels fastest in rigid media, such as steel, slower in liquid media, such as water, and slowest of all in gases, such as air. The following table shows the approximate speed of sound, measured in feet per second, in air, water, and steel.

Write a program that displays a menu allowing the user to select air, water, or steel. After the user has made a selection, the number of feet a sound wave will travel in the selected medium should be entered. The program will then display the amount of time it will take. (Round the answer to four decimal places.)

Input Validation: Decide how the program should handle an illegal input for the menu choice or a negative value for the distance.

Write a program that asks for the number of calories and fat grams in a food. The program should display the percentage of calories that come from fat. If the calories from fat are less than 30 percent of the total calories of the food, it should also display a message indicating the food is low in fat.

One gram of fat has 9 calories, so

Calories from fat = fat grams * 9

The percentage of calories from fat can be calculated as

Calories from fat / total calories

Input Validation: The program should make sure that the number of calories is greater than 0, the number of fat grams is 0 or more, and the number of calories from fat is not greater than the total number of calories.

Write a program that calculates and displays a person’s body mass index (BMI). The BMI is often used to determine whether a person with a sedentary lifestyle is overweight or underweight for his or her height. A person’s BMI is calculated with the following formula:

$$BMI = weight * 703/height^2$$

where weight is measured in pounds and height is measured in inches. The program should display a message indicating whether the person has optimal weight, is underweight, or is overweight. A sedentary person’s weight is considered to be optimal if his or her BMI is between 18.5 and 25. If the BMI is less than 18.5, the person is considered to be underweight. If the BMI value is greater than 25, the person is considered to be overweight.

Write a program that asks for the name of a pole vaulter and the dates and vault heights (in meters) of the athlete’s three best vaults. It should then report in height order (best first), the date on which each vault was made, and its height.

Input Validation: Only accept values between 2.0 and 5.0 for the heights.

Write a program that asks for the names of three runners and the time it rook each of them to finish a race. The program should display who came in first, second, and third place.

Input Validation: Be sure the names do not overflow the arrays. Only accept positive numbers for the times.

Write a program that displays the following menu:

Geometry Calculator

  1. Calculate the Area of a Circle
  2. Calculate the Area of a Rectangle
  3. Calculate the Area of a Triangle
  4. Quit

  Enter your choice (1—4) :

If the user enters 1, the program should ask for the radius of the circle and then dis- play its area. Use the following formula:

$$area = \pi r^2$$

Use 3.14159 for $\pi$. and the radius of the circle for r. If the user enters 2, the program should ask for the length and width of the rectangle and then display the rectangle's area. Use the following formula:

area = length * width

If the user enters 3 the program should ask for the length of the triangle's base and its height, and then display its area. Use the following formula:

area = base * height * .5

If the user enters 4, the program should end.

Input Validation: Display an error message if the user enters a number outside the range Of 1 through 4 when selecting an item from the menu. DO not accept negative values for the circle's radius, the rectangle's length or width, or the triangle's base or height.

A bank charges $10 per month plus the following check fees for a commercial checking account:

$.08 each for 20-39 checks$.06 each for 40-59 checks
$.04 each for 60 or more checks

Write a program that asks for the number of checks written during the past month, then computes and displays the bank's fees for the month.

Input Validation: Decide how the program should handle an input of less than 0.

Software Sales
A software company sells a package that retails for $99. Quantity discounts are given according to the following table.

Write a program that asks for the number of units sold and computes the total cost of the purchase.

Input Validation: Make sure the number of units is greater than 0.

Sometimes either a switch statement or an if/else if statement can be used to implement logic that requires branching to different blocks of program code. But the two are not interchangeable.

$A)$ Under what circumstances would an if/else if statement be a more appropriate choice than a switch statement?
$B)$ Under what circumstances would a switch statement be a more appropriate choice than an if/else if statement?
$C)$ Under what circumstances would a set of nested if/else statements be more appropriate than either of the other two structures?

Each of the following program segments has errors. Find as many as you can.
A)

cout << "Enter your 3 test scores and I will ";
     << "average them:";
int score1, score2, score3,
cin >> score1 >> score2 >> score3;

double average;
average = (score1 + score2 + score3) / 3.0;
if (average = 100);
    perfectScore = true;// Set the flag variable
cout << "Your average is " << average << endl;
bool perfectScore;
if (perfectScore);
{
    cout << "Congratulations!\n";
    cout << "That's a perfect score.\n";
    cout << "You deserve a pat on the back!\n";

B)

double num1, num2, quotient;

cout << "Enter a number: ";
cin >> num1;
cout << "Enter another number: ";
cin >> num2;

if (num2 == 0)
    cout << "Division by zero is not possible.\n";
    cout << "Please run the program again ";
    cout << "and enter a number besides zero.\n";
else
    quotient = num1 / num2;
    cout << "The quotient of " << num1 <<
    cout << " divided by " << num2 << " is ";
    cout << quotient << endl;

C)

int testScore;

cout << "Enter your test score and I will tell you\n";
cout << "the letter grade you earned: ";
cin >> testScore;

if (testScore < 60)
    cout << "Your grade is F.\n";
else if (testScore < 70)
    cout << "Your grade is D.\n";
else if (testScore < 80)
    cout << "Your grade is C.\n";
else if (testScore < 90)
    cout << "Your grade is B.\n";
else
    cout << "That is not a valid score.\n";
else if (testScore <= 100)
    cout << "Your grade is A.\n";

D)

double testScore;

cout << "Enter your test score and I will tell you\n";
cout << "the letter grade you earned: ";
cin >> testScore;

switch (testScore)
{ case (testScore < 60.0):
    cout << "Your grade is F.\n";
    break;
case (testScore < 70.0):
    cout << "Your grade is D.\n";
    break;
case (testScore < 80.0):
    cout << "Your grade is C.\n";
    break;
case (testScore < 90.0):
    cout << "Your grade is B.\n";
    break;
case (testScore <= 100.0):
    cout << "Your grade is A.\n";
    break;
default: cout << "That score isn't valid\n"; }

The following programs has errors. Find as many as you can. // This program uses an if/else if statement to assign a // letter grade (A, B, C, D, or F) to a numeric test score. #include using namespace std; int main () { int testScore; cout << "Enter your test score and I will tell you\n"; cout << "the letter grade you earned: "; cin >> testScore; if (testScore < 60) cout << "Your grade is F.\n"; else if (testScore < 70) cout << "Your grade is D.\n"; else if (testScore < 80) cout << "Your grade is C.\n"; else if (testScore < 90) cout << "Your grade is B.\n"; else cout << "That is not a valid score.\n"; else if (testScore <= 100) cout << "Your grade is A.\n"; return 0; }