Demand

Being a senior student means:

You love seeing movies

especially at movie theaters like CINEPLEX ODEON.

You may grudgingly pay around $12 for a ticket, but a movie is a movie, and you are generally guaranteed a good time. 
This is the element of Demand.  If refers to the various quantities of a good/service that people will be willing and able to purchase at various prices during a period of time.  
But what if the price of a movie suddenly skyrocketed to
$25?
$30?
Or consider if your usual Small Popcorn went from $4.75 to $8.00 instead. 
As the price of a product goes DOWN, the quantity demanded increases, and as the price of a product goes UP, the quantity demanded decreases.  However, movie theaters raise prices MINUTELY.
Looking at the prices of movie tickets/food, someone may think twice about seeing the newest flick...especially if the movie isn't "worth it".

Note: there is an inverse relationship between price and quantity demanded

The factors that shift demand include:

Income:

If you receive a pay increase, your demand for movies will increase because you can be more frivolous with your money

OR

If you have a pay decrease, your demand for movies will decrease because you likely can't afford to spend money on entertainment.

Prices of Related Goods:

1) Substitutes: goods that can replace each other e.g Large Popcorn + a Small Fries both=$5.00
The price of Popcorn increases, so the demand for Fries increases
OR
The price of Popcorn decreases, so the demand for Fries decreases.

2) Complements: goods that go together e.g. Chocolate Bar + some Candy
The cost of Chocolate Bars decreases, so the demand for Candy decreases
OR
The cost of Candy increases significantly, so the demand for Chocolate Bars increases.

Tastes/Preferences:

Consumers want to see the newest action/romance/drama/comedy movie, so demand for movies increases
OR
There aren't any "good" movies coming out, so demand for movies decreases.

Expectations:

VS.

It's July and theatres are preparing for Harry Potter and the Deathly Hallows Part II to come out, so demand for tickets increases
OR
For 4 months, theaters only show movies that appear "stupid", "boring", or "lame", so demand for tickets decreases.

 Population:

More people (especially senior students) move to your town/city, so demand for a movie theater increases
OR
Many senior students in your town/city move away to attend college/university/work, so demand for a movie theater decreases.

Opportunity Cost

As a senior student, you make economic choices daily.

HOW?

Imagine you want to watch a movie at the local movie theater.  

You first have to consider the price of Admission:

General (14-64) $11.75

Child (3-13) $8.99

Senior (65+) $8.99

OR whether you want to see the movie in 3D:

3D General (14-64) $14.75

3D Child (3-13) $11.99

3D Senior (65+) $11.99

However, seeing a movie also involves purchasing food and drink. 

   

As the consumer you have to consider: what size drink/popcorn you want, the quantity of each item, and if you want to also purchase other food items such as chocolate, candy, ice cream, hot dogs, fries, etc.

Here is a list of food/drink prices for a normal theatre 

(like CINEPLEX ODEON):

Pop

S-$4.50 M-$4.75 L-$5.00

Popcorn

S-$4.75 M-$5.25 L-$5.00

Chocolate Bar

$2.50

Ice Cream

S-$3.50 M-$3.75 L-$4.00

Candy

$3.50

Hot Dog

$6.50

Fries

S-$5.00 M-$6.00 L-$6.25 

Imagine you only have a budget of $30.00.  How will you spend your money?

This is the dilemma of opportunity cost.

Opportunity cost refers to the alternative(s) that is/are sacrificed when (a) choice(s) is/are made.  Other examples of opportunity cost involved with this scenario include: if you only have a certain amount of time to watch a movie, or if you have an economics test tomorrow but choose to see a late night movie instead.

Therefore, if you have a scarcity of time, money, etc. at a movie theater, you have to make choices based upon that scarcity.  Should I choose to watch a movie another night when I do not have to study for a test?  Should I buy the chocolate bar instead of the candy?  Should I purchase a Small pop/popcorn instead of a Large?

Each choice will provide

a low opportunity cost: the choice(s) made incur(s) a high benefit

AND/OR

a high opportunity cost: the choice(s) made incur(s) a low benefit 

to determine the best decision.