# Hints

## 1. Define the expected oven time in minutes

* You need to add a new entry to the table `lasagna` with the key `oven_time` and the expacted oven time in minutes.
* The value has to be a number.

## 2. Calculate the remaining oven time in minutes

* You need to write the body for the function `remaining_oven_time`.
* You need to return a number.
* You can use the [arithmetic operator](https://www.lua.org/manual/5.4/manual.html#3.4.1) for substraction.

## 3. Calculate the preparation time in minutes

* You need to write the body for the function `preparation_time`.
* You need to return a number.
* You can use the [arithmetic operator](https://www.lua.org/manual/5.4/manual.html#3.4.1) for multiplication.

## 4. Calculate the elapsed working time in minutes

* You need to write the body for the function `elapsed_time`.
* You need to return a number.
* You can [call](https://www.lua.org/manual/5.4/manual.html#3.4.10) one of the other functions you've defined previously.
* You can use the [arithmetic operator](https://www.lua.org/manual/5.4/manual.html#3.4.1) for addition.