# Sony’s “The Interview” Math Problem

In December of 2014, Sony released the movie The Interview online after threats to theaters cancelled the debut in theaters. As originally reported in Wall Street Journal, the sales figures reported in January contained an interesting math problem appropriate for algebra students.

The following January, Sony reported sales of \$31 million from the sales and rentals of The Interview. They sold the movies online for \$15 and rented through various sites for \$6. If there were 4.3 million transactions, how many of the transaction were sales of the movie and how many of the transactions were rentals?

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# Doubling Time on Gilligan’s Island

Populations are often described by their doubling times. The doubling time is the amount of time it takes a population to double. We can calculate the doubling time of an increasing exponential model by examining its graph carefully. Since students seem to enjoy themodel for population growth on Gilligan’s Island, I like to use it to illustrate doubling in an exponential function. Continue reading Doubling Time on Gilligan’s Island

# What Should Have Happened on Gilligan’s Island?

Last week the students in my College Algebra started exponential functions. They got started on the basics of exponential graphs, when they are increasing and decreasing, and exponentials with a base e. With these basics completed, they are working on an Applications Quiz this week. To get them started on this material, I introduced an application based on Gilligan’s Island.

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# Introducing Piecewise Functions

After weeks of linear functions, quadratic functions, and matrices, I needed an introductory example for piecewise functions. Examples like this catch student’s attention and get them thinking about how math might be used in real life. I used the example below in class and in the form you see below for my online classes.

How many of you have a car? How many of you have car insurance? In most of my classes, almost every student has a car and insurance. Yet many people are completely unfamiliar with how their insurance works and what they pay annually for that insurance.

For most people, the most important part of their insurance is the premium they pay every six months. A typical premium is \$600 every 6 months. This premium may vary depending on the deductible amount. The deductible is the amount you must for a claim before the insurance company pays the rest of the claim. A higher deductible typically means a lower premium. Comparatively speaking, a lower deductible means a higher premium.