Lasagna

Instructions

You're going to write some code to help you cook a lasagna from your favorite cookbook.

You have five tasks, all related to cooking your recipe.

1. Define the expected oven time in minutes

Set the $Lasagna::ExpectedMinutesInOven variable with how many minutes the lasagna should be in the oven. According to the cooking book, the expected oven time in minutes is 40:

$Lasagna::ExpectedMinutesInOven
# => 40

2. Calculate the remaining oven time in minutes

Modify the Lasagna::remaining_minutes_in_oven subroutine, which takes the actual minutes the lasagna has been in the oven as an argument, to return how many minutes the lasagna still has to remain in the oven, based on the expected oven time in minutes from the previous task.

Lasagna::remaining_minutes_in_oven(30)
# => 10

3. Calculate the preparation time in minutes

Modify the Lasagna::preparation_time_in_minutes subroutine, which takes the number of layers you added to the lasagna as an argument, to return how many minutes you spent preparing the lasagna, assuming each layer takes you 2 minutes to prepare.

Lasagna::preparation_time_in_minutes(2)
# => 4

4. Calculate the total working time in minutes

Modify the Lasagna::total_time_in_minutes subroutine that takes two arguments: the first argument is the number of layers you added to the lasagna, and the second argument is the number of minutes the lasagna has been in the oven. The subroutine should return how many minutes in total you've worked on cooking the lasagna, which is the sum of the preparation time in minutes, and the time in minutes the lasagna has spent in the oven at the moment.

Lasagna::total_time_in_minutes(3, 20)
# => 26

5. Create a notification that the lasagna is ready

Modify the Lasagna::oven_alarm subroutine, which does not take any arguments, to return a message indicating that the lasagna is ready to eat.

Lasagna::oven_alarm()
# => "Ding!"