Expression Exercises

Invent something like the following. Each program will get input from cin, and, if the input was successful, will store the input into one or more variables. Decide if each variable should be an int or a double, and pick a good name for each variable, Write an expression to compute the answer. Store the value of the expression into another variable, and then feed this other variable to cout.

1. [1 human year = 7 dog years.
   Good names for the two variables might be humanYears and dogYears.]
   How old are you? 20
   That’s 140 dog years!
2. [Cook the turkey for 13 minutes per pound.]
   How many pounds does the turkey weigh? 12
   Then you have to cook it for 146 minutes.
   That’s 2 hours and 26 minutes.
3. [Define four variables to hold the four input numbers.]
   How many pennies do you have? 3
   How many nickles do you have? 5
   How many dimes do you have? 10
   How many quarters do you have? 6
   Then you have a total of 268 cents.
   That’s 2 dollars and 68 cents.
4. [Dolbear’s law: chirps per 15 seconds, plus 40, equals the temperature in Fahrenheit.]
   How many times did the cricket chirp in 15 seconds? 30
   Then the temperature is 70 degrees Fahrenheit.
   That’s 21.1111 degrees Celsius.
5. How many quarters do you need for the washer? 20
   How many quarters do you need for the dryer? 5
   Then you need a total of 25 quarters.
   That’s 6 dollars, and maybe some change.
   [If we had already covered if statements, I could ask you to put the “and maybe some change” into an if statement because we don’t always want to output this phrase. But we haven’t, so I can’t.]
6. [1 degree = π/180 radians.]
   What is the size of your angle in degrees? 90
   Then the size of your angle in radians is 1.5708
7. [The New York City taxi fare (not counting the various surcharges) is three dollars, plus 70¢ for each 1/5 mile.]
   How many miles are you going? 3
   The taxi ride will cost 13.5 dollars.