Tuesday, February 21, 2006

Remember Math?

Does anyone remember math? Not the practical kind you use in real life, like figuring 15% for a tip at Longhorn Steakhouse, but the useless high-school kind? I've been doing a few practice GRE math questions today and I'm a little shocked at how very little of that stuff I do actually remember. Did you know that all of the exterior angles of a figure always add up to 360 degrees? I sure didn't. I'm not sure I ever knew that. I don't even remember how to multiply fractions anymore. So doing these practice GRE math questions has been an exercise in humility. I know so very very little. When I go in tomorrow for a "practice" test at a Kaplan testing center, I'm fully expecting to embarrass myself on the quantitative section. Here's an example of a question that I took a good look at, and then straight up gave up on. (I'm choosing the hardest one I've seen so far just to keep everyone on their toes):

17.) Jane must select three different items for each dinner she will serve. The items are to be chosen from among 5 different vegetarian and 4 different meat selections. If at least one of the selections must be vegetarian, how many different dinners could Jane create?
a) 30
b) 40
c) 60
d) 70
e) 80

The explanation in the back of the book made my mind hurt. I encourage you to give it a shot. 1 in 5 of you will get it right. Or will you? Or are those odds? I don't know odds, and 1 in 5 of you probably won't get it. 1 in 10? Less than that? Peggy?

Anyway, if anyone is interested, I'll post up the answer and the explanation tomorrow.

15 comments:

blankfist said...

The answer is 80.

Are you telling me, boy, Math has been kicking my everloving butt these days. I've been building a miniature golf game engine in Flash, so I had to figure out all that math I forgot and then some I never knew. Figuring out a balls angle and trajectory using cosine and sine... ugh!... and the PI times the angle divided by 180 gives you the.... ARGH!

But, now that I know all that stuff again, it does fill you with a sense of accomplishment.

harwell said...

"Figuring out a ball's angle and trajectory using cosine and sine... ugh!"

Hehehehe.

Shannon said...

Hey BRAIN, the tip should be 20%. Go back to school.

Anonymous said...

Harwell, must you take it there?

food for thought said...

Roll Call responds this morning Sunday’s Meet The Press appearance by Rep. Jane Harman (D-Calif.), the ranking member on the House Intelligence Committee, reporting “In a weak performance, Harman actually tried to explain her lack of oversight by suggesting that she, like Sen. Jay Rockefeller (D-W.Va.), her counterpart on the Senate Intelligence Committee, had no one to talk to about their concerns….How about picking up the phone and calling the president, the vice president, House Intelligence Chairman Pete Hoekstra (R-Mich.), Senate Intelligence Chairman Pat Roberts (R-Kan.), Speaker Dennis Hastert (R-Ill.), Defense Secretary Donald Rumsfeld, then-National Security Adviser Condoleezza Rice, House Minority Leader Nancy Pelosi (D-Calif.), Senate Minority Leader Harry Reid (D-Nev.) or the head of the NSA surveillance program? Or, if the phone wasn’t her complaint line of choice, how about a letter to any of the above officially raising her objections, and which would have required an official reply? Harman talked to no one.”

blankfist said...

Man, that food for thought sure knows how to kill everyone's good times... you're evil, food for thought... my brain is still starving!

harwell said...

Gretch took a shot at this last night and yeah, Heath's right - it's 80.

More important question, are you preparing to apply for Grad School, el Crane??? Do tell.

Also, if you are and if it's for Creative Writing, know that some schools don't require GRE scores. Though I imagine you already checked up on that. Or you're just being a nerd and taking the GRE to see how smart you are(n't). I never can tell with you.

Nathan said...

brian, why are you going into the Kaplan learning center?

judgeholden said...

No, I decided against any sort of higher learning beyond what I've alread acquired, humbly at an art school, and I'm pretty sure I wouldn't have the patience to trudge through another two to four years of what I experienced at NCSA. A lot of incredibly gay experiences of teachers with my cornhole.

blankfist said...

Geez, Crane, what an incredibly odd thing for you to say, as if you weren't Crane at all.

Me suspicious.

JudgeHolden said...

Yes, it is indeed odd that I would talk so freely about those crazy nights at NCSA I try every night to forget. I must have been on one of my usual Thursday afternoon PCP benders when I wrote that.

80 is indeed right, Heath and Gretch are both correct. Color me impressed (but not badd. Anything but badd). I could post up how the GRE book says to solve it out, but that's a lot of typing and you guys are obviously mathletes already, so I won't post it up unless you want me to. My own math skills are so hopelessly atrophied, that the math questions in my GRE book literally gave me a headache. One thing I hadn't considered in this half-assed, non-committal sidelong approach towards thinking about grad school of some kind, is that there is actual pain involved in preparing for maybe, perhaps, possibly... taking the GRE. Is it possible that if you neglect using a part of your brain, say the part that once did math, that to fire it up again could cause you pain? What simple machines we are.

blankfist said...

It's tough when people say "combinations" and "factorials" and show you stuff like this: C(n,r)=n!/(n-r)!

What does that mean?!?!?!?! Goobledygook!!! Lorem Ipsum!!!

Okay, here it is... 5 veggie + 4 meat = 9 total foods. From those 9 you have to select 3 combinations. That's the nine(9x8x7x6x5x4x3x2x1) divided by the result of the 3 plate combination (3x2x1) multiplied taking the 3 from the nine which would give you 6 (6x5x4x3x2x1). This will give you 84. Do the math.

But 84 isn't the answer, because 84 is the TOTAL possible combinations. Now we have to remove the combinations that would NOT contain at least ONE veggie dish.

Here's how... Remove all possible combinations of 3 out of the 4 meat selections, like this: take the 4 (4x3x2x1) divided by the result of the 3 plate combination (3x2x1) multiplied by the 3 taken from the 4 (1x1). This will give you 4.

Factorials are a lot easier when you use google's calculator. Instead of typing 9x8x6x5x4x3x2x1, you can just write "9!". That's all that little exclamantion means. Now, put the below into google and hit search.

9! / ((3!)*(6!)) - 4! / ((3!)*(1!))

Google will come back with 80. See? 9! = 9x8x7x6x5x4x3x2x1... easy huh? Of course, I wouldn't have known this if it weren't for me checking the internet on how to so all this stuff... if I had that problem ON PAPER in front of me without the internet, then that question alone would probably have taken me a good thirty minutes to deduce... and even then, I always seem to mess up somewhere in my multiplication. I'm human.

blankfist said...

If you had four veggies and five meats, and you need to find the maximum number of combinations of 3 that included at least ONE veggie, then the problem would look like this:

9! / ((3!)*(6!)) - 5! / ((3!)*(2!))

...which equals 74. As you can tell, I'm incredibly BORED at work.

Anonymous said...

Boring!

blankfist said...

Waterworld hat?