Debate question need thoughts PLEASE!

Factual Questions
1

hello,
in physics two days ago our professor told a story of two kids who had gotten A’s on all their tests at a University, when the final came they had been out partying and missed the test the next morning. To get a make up they told the professor they had a flat tire. On the make up quiz there was two questions the first worth 5 points was quite simple and they both got it right, on the back was the other question worth 95 points it read “Which tire”
well we all got a laugh until a kid asked if they got it right. our professor being the math geek he is began to work out the probability however some of us felt he was wrong and some felt he was right. We now have a 10 point wager going on this and altho he is discussing it with a math professor i was hoping to see what you all thought.

basically what is the odds that the two kids both chose the corect flat tire.

thanks
adiso
the mighty quinn

2

12.5%

They each have a 1 in 4 chance of choosing any given tire, so .25 x .25 = .125 .

Now, I’m sure someone will come along in a few minutes and show me where I’m wrong… :eek:

“Sometimes I think the web is just a big plot to keep people like me away from normal society.” — Dilbert

3

Well, I was no math major, but why wouldn’t each person have a 25% chance? If one person chose driver’s side front, then doesn’t the other person have a one-in-four shot to also pick that tire? There really isn’t a “right” answer, they just both have to choose the same one.

Hey, is this my 100th post? Woo hoo!

“It says, I choo-choo-choose you. And it’s got a picture of a train.”
– Ralph Wiggum

4

I’ll probably get flamed for this for being too simple but it seems to me that the answer is 25%.

Student 1 picks a tire…doesn’t matter which.

Student 2 now has a 1-in-4 chance of picking the same tire as the first student (assuming the car had four tires).

This reminds me a bit of the Monty Hall dilema somewhere in the archives. I never did buy into that one completely.

5

Well, the way I figured it, the odds are 16:1 (4:1 x 4:1) or 6.66%.

But math was never my strong subject.

Who’s next?

I understand all the words, they just don’t make sense together like that.

6

This is easy to figure because there are not that many possibilities. I will do it the long way to make it clear.

Here is a list of all the possible results of two people picking random tires. I’ll just number them 1-4.

  1. 1-1 <----A winner
  2. 1-2
  3. 1-3
  4. 1-4
  5. 2-1
  6. 2-2 <----Winner #2
  7. 2-3
  8. 2-4
  9. 3-1
    10)3-2
    11)3-3 <----Winner #3
    12)3-4
    13)4-1
    14)4-2
    15)4-3
    16)4-4 <----Winner #4

Thus, you see there are four winners out of 16 equally probable possibilities. A 25% chance.

Spring Ice: 2 parts gin, 1 part Cointreau, 1 part Midori, 2 parts fresh squeezed lime, 7-up to fill - Garnish: Orange slice in bottom of glass.

7

Zero as there WAS no flat tire!

8

The odds are 25%.

The tire chosen doesn’t matter.

The odds that the first student will pick the same tire as the first is 100%.

The odds that the second student will pick the same tire as the first is 25%.

Now, if there were a third, the odds would be 6.25% that they all matched.

You must unlearn what you have learned. – Yoda

9

Whee! How many mistakes can I make in one post? Lets see…

First, .25 x .25 = .0625, not .125 . Not that that matters, neither one is the correct answer.

The first student always picks the same tire as the first student (duh!) so 100% there.

The second student then has a 25% chance of picking the same tire as the first.

So… 1.00 x .25 = .25 .

The correct answer is 25%.
I’m going to go hide under a rock now…

“Sometimes I think the web is just a big plot to keep people like me away from normal society.” — Dilbert

10

Well, the way I see it, the first kid has four choices & the second kid has four choices. Okay? They aren’t looking at each others papers. Thus, there would be 4X4 or 16 possible outcomes. And a 2 (guys)/16(Choices) chance they BOTH got it right, not 25%.

11

Keep in mind that there is no “right” answer; the professor is just checking to see that both students put down the same tire. So if they both put down the front left tire, they got it right. If they both put down the front right tire, they got it right, and so on.

I’m pretty sure it’s a 25% chance. The question can be simplified to be “What are the chances student B puts down the same answer as student A when there are four choices?” Student A puts down whatever he damned well pleases; student B has a 1 in 4 chance of putting down the same answer.

12

Hate to pick nits y’all (yeah, right!) but the OP says…

So there is a “correct” tire, even if, in real life, the Prof didn’t know which it was.

13

If you want to think of it that way, the chance is 0%, since there can’t be a correct flat tire if there wasn’t a flat tire in the first place.

I think it’s reasonable to assume he was after what’s the chance the two students would get away with it, and in that case, they just have to have matching answers.

If that’s not what you were after, then by all means, speak up.