Comments on: [It Got Away] Red Rock Coffee

By: Ed Parker

Ed Parker — Wed, 12 Jan 2011 20:24:04 +0000

Forget the analysis of the cost per shot and all that. Take the class down on successive days and do some imbibing. How many servings of each does it take to get some real caffeine jitters going? This is something that can be quantified, results can be studied with 5 number summaries, scatter plots, whatever you like.
It might be necessary to devise a “jitter scale.”
I worked for a principal who had the strongest jitter juice I have ever encountered in my career, and she always offered coffee before a “sit down and discuss.” I’m embarrassed to recall how many sessions it took before I learned to decline the coffee.

By: DavidC

DavidC — Sat, 08 Jan 2011 18:25:58 +0000

My mind went the same place as Amulya’s… I think that’s a nice question.

I don’t like “price per shot per ounce” –it’s not claiming to be the most concentrated caffeine for you money, just the most caffeine for your money.

(Surely they sell espresso shots, and surely those would win on Dan’s terms.)

By: Jackie Ballarini

Jackie Ballarini — Sat, 08 Jan 2011 03:07:05 +0000

Thank you for sharing this part of your process. Nice to know (well, be told again), that every idea you have just doesn’t magically come forth as a complete WCYDWT.

By: Amulya Iyer

Amulya Iyer — Thu, 06 Jan 2011 14:23:14 +0000

This definitely still works, and the part that ‘got away’ seems to make the problem that much juicier.

The follow up question now becomes: How strong does a Red Rock employee have to brew their coffee for their claim to be true? (or something to that nature)

New questions to anticipate:

What units should we solve this problem in?
How many mg of caffeine in a shot of espresso?
How many ounces in a shot of espresso?

To quote a previous WCYDWT: You’re thinking. You’re Googling. You’re calculating.

By: Mr. Lovell

Mr. Lovell — Thu, 06 Jan 2011 02:08:37 +0000

I also think there is madness in your method, even before your wife’s comment. Forget your wife, let’s assume caffeine is only contained in the shots. You are skeptical of the claim that Red Eye has “the most caffeine for your money”. You should be able to assess that as is, without needing to transform the table.

This is because each column in the original price table compares the 4 drinks by a common measure (column 1 is per 2 shots per 12 oz for all 4 drinks, column 2 is per 2 shorts per 16 oz, and column 3 is per 4 shots per 20 oz). So you can already conclude that Red Eye is not the cheapest so their claim is false.

You should be able to see that the rank of drinks from cheapest to most expensive in all 3 columns is the same before and after you transform the table.

By: Eric

Eric — Thu, 06 Jan 2011 01:28:21 +0000

With my geometry students, I compare the difference in price for 12″, 14″ and 16″ pizza to find the cost of pizza per square inch.

For extra fun, compare th prices if you throw out the crust.

By: AnonLurker

AnonLurker — Wed, 05 Jan 2011 20:38:36 +0000

I don’t get why you’d divide by ounces, anyway. Why does a shot of caffeine + 12 ounces of milk have a different effect than a shot of caffeine + 20 ounces of milk, if you drink the whole thing either way? The calculation you did doesn’t make sense to me.

Then again, I don’t drink coffee, so what do I know about any of this? Nothing.

By: Bob Mathews

Bob Mathews — Wed, 05 Jan 2011 20:25:26 +0000

And I’m betting their menu is a misprint anyway. There’s probably 3 shots in a medium. Why have 2 in both S and M, then jump to 4 in a L? Just speaking as an avid coffee hound.

By: JDL

JDL — Wed, 05 Jan 2011 19:35:36 +0000

This unit still works.

In fact, I’d be surprised if nobody asks what else is in the red eye while you’re doing your questioning thing. If nobody asks, continue on and be as less-helpful as possible.

If math is supposed to teach you logical thinking and problem solving, I don’t see why this wouldn’t work – it’s still a whole lot more helpful than the stuff in the textbooks :)

Does the fact that a shot = 2/3 oz add any complexity to the problem? I’m not a math teacher and it’s late in the day for me… haha.