Random Math Problem

[chrishuff]

Julia has absolutely no knowledge of physics whatsoever. To avoid getting a zero on the physics portion of the UIL Science test, she decides to gamble and guess answer choices in an attempt to score points on that section of the test. Knowing that the probability of guessing the correct answer to a question is 20%, and that getting 5 questions right while getting 15 questions wrong is breaking even, what is the probability and the odds of her scoring above a zero on the physics section of the test? Would the probability and/or the odds change if she guessed all A's, B's, C's, D's, or E's for all 20 physics questions on the test?

[nsguy1350]

Hmm... you made this up.
I thought I had a solution, but I'm going to have to reconsider it.
I'll try to figure it out later.

[chrishuff]

[nsguy1350]

If you get 20% right, on average, you should lose 8 points and gain 6. This is -2 for every 5, or a -8 average. That should be enough to deter them.
However, if you get 2 more right, you're positive. You could also get 2 more wrong and go -16.

[BlasianAsian]

Why would you need to explain it to them via math problem? You could always use good old common sense.

Eliminate three answers, guess.

Other than that, not worth it.

[nsguy1350]

Eliminate two, you get a good chance. Eliminate 1, you're breaking even.
Eliminate none, you're at a loss. Eliminate 3, you're doing well.
Hopefully you can eliminate 4.
Don't eliminate 5!!!

[BlasianAsian]

Life hates me, so I usually don't guess. Esp on science. God.

I remember I took a social studies test.

Which state has the lowest alcohol consumptions rate?
A. Utah
B. Some Random Place
C. Kentucky
D. Another Random Place
Hmm... which one, which one?
It CAN'T be Utah, where all the mormons are, can it?!
Facepalm. I picked the fried chicken. Epic fail.

This is what happens when you live under a rock. I just listened to the song, "I'm awesome", a couple of weeks ago. Shame on me.

[nsguy1350]

My rock is bigger and heavier than yours :p
I don't consider myself too nerdy.. you know, besides doing UIL (not the typical nerd voice, or dress, etc.), but I'm definitely not your jock-type.