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I need a little math help. I suck at permutations, and such.

Here's what I am trying to figure out.

I have 5 mutable positions.

First position can be either: a/b
Second: c/d
Third: e/f
Fourth: g/h
Fifth: i/j/k

I think the number of possibilities should be 48, but I don't know how to calculate this.

Thanks!

BTW, this isn't for class - it's for work.

You're right. There are 48.
the first four are just a binary number
2^4 = 16 (think of each as an on/off state). The last one gives you three additional branches. 3 * 2^4 = 48.

Or even simpler 2*2*2*2*3 = 48.

The formula is just (number of states)^(number of instances of those states)

2*2*2*2*3, so 48.

Damn you Dr Fade McNinja!

Thanks guys. That's how I calculated it, but I haven't tried math like this in quite some time. It just seemed too easy. Thanks!

If you're looking for information on counting problems (such as if this comes up at work again), look up "combinatorics".

This also has applications when playing the lottery.
Mostly the results should just tell you why you shouldn't play the lottery.

--Patrick

PatrThom said:

This also has applications when playing the lottery.
Mostly the results should just tell you why you shouldn't play the lottery.

--Patrick

Click to expand...

Definitely. The lottery preys on the dim-witted and the desperate.

On a separate note
What's everyone's highest course of mathematics taken academically?
Started calculus this semester

Had to take 5 Calc courses and a linear/matrix algebra course that hurt my brain.

Also "Principles of nuclear magnetic resonance" in grad school was a mindfuck (not the good kind, the bend-over-and-take-it-all kind).

Calculus III, Physics II, and Discrete Math

Discrete Math sucked, I liked Physics (well, mechanics), and Calculus wasn't all that interesting.

Managerial Accounting. *sob*

Never advanced beyond secondary school calculus.
Still find it all quite fascinating, though.

--Patrick

I'm a (geo)physicist, so I have a lot of math under my belt. Don't know (ironically) how to quantify it, since a lot of it came from physics study and research. Formally, up through probably junior or senior year of a math major, when things get all number-theoryish, which means "useless to a physicist". Though I still like reading about it. Tons of computer science math and probability and statistics. Most of my research is in diff eq. solutions and probability theory.