Think you're clever? Yami tests you...

Desiigner

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This dude... XD
Who would do maths if not forced to? And even have fun whilst doing it?
 

Pumpkin Ninja

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7. (1/40)*(1/39)*(1/38)*(1/37)*(1/36)?

For the first question, why do you divide by 2?



These questions are all part of my data management class this semester so it's sad that I forgot how to do them. I'm doing well in the class too :(
 

Yami Silver

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1. n(n-1)?
Very close. I've put my solution in the spoiler.
Person A has n-1 many people to shank hands with.
Person B also has n-1 many people to shake hands with.
However, we're going to take away one from that because we've already counted the handshake AB when we counted person A's handshakes.
So then, as it stands, we have n-1 + n-2. Next we move onto person C.
Using the same logic, we say n-1 minus 2 more because we've already counted AC and BC.
Then we can say that we our solution is n-1 + n-2 + n-3... + 2 + 1 which is the sum for positive integers up to n-1. This simplifies to (n)(n-1)/2
 

Legendary Saiyan

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Oh, I never knew it was called the FOIL method. I thought it was called the difference of two squares lol

Oh you're in London that's probably why. I'm in USA and we call it the FOIL method because it means First Outer Inner and Last.
 

Pumpkin Ninja

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Oh you're in London that's probably why. I'm in USA and we call it the FOIL method because it means First Outer Inner and Last.
The foil method is for all of those bracket type of questions while the one Yami posted specifically was difference of squares, a type of FOIL question.
 

Yami Silver

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7. (1/40)*(1/39)*(1/38)*(1/37)*(1/36)?

For the first question, why do you divide by 2?



These questions are all part of my data management class this semester so it's sad that I forgot how to do them. I'm doing well in the class too :(

All the questions? Even the geometry and number theory? :p

For the first question, the sum of positive integers up to (n-1) is n(n-1)/2. I can prove that if you want.


Also, your question 7 is also very close. I'll leave my solution here in a spoiler if you want to look at it.
Ok, there are 5 Exodia cards and 40 cards in the deck.
Let's label our Exodia cards A, B, C, D and E
The probability we draw A is 1/40
The probability we draw B next is 1/39.
The probability C is next is 1/38 D following is 1/37 and E following is 1/36
So, in one victory scenario, there is a 1/(40*39*38*37*36) probability of a 0 turn win
However, that is not the only victory scenario; there are many more.
How many ways can we rearrange cards ABCDE? 5! = 5*4*3*2*1 (which I can prove if you want me to).
Therefore there are 5! victory scenrios and 40*39*38*37*36 total scenarios.
Therefore, the answer is (5*4*3*2)/(40*39*38*37*36) which is usually written as 5C40
 
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Pumpkin Ninja

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All the questions? Even the geometry and number theory? :p

For the first question, the sum of positive integers up to (n-1) is n(n-1)/2. I can prove that if you want.


Also, your question 7 is also very close. I'll leave my solution here in a spoiler if you want to look at it.
Ok, there are 5 Exodia cards and 40 cards in the deck.
Let's label our Exodia cards A, B, C, D and E
The probability we draw A is 1/40
The probability we draw B next is 1/39.
The probability C is next is 1/38 D following is 1/37 and E following is 1/36
So, in one victory scenario, there is a 1/(40*39*38*37*36) probability of a 0 turn win
However, that is not the only victory scenario; there are many more.
How many ways can we rearrange cards ABCDE? 5! = 5*4*3*2*1 (which I can prove if you want me to).
Therefore, the answer is (5*4*3*2)/(40*39*38*37*36)
Yeah, I kind of just skimmed the questions and those two caught my eye, didn't see the geometry or number theory one.

So 40C5?

For my math classes, I kind of just cram the knowledge in my head an hour before tests so after the test it escapes my mind. I'm gonna have a lot of studying to do come exam time. Also, these questions never made much sense to me logically, I'd just follow the formulas.
 

Yami Silver

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Yeah, I kind of just skimmed the questions and those two caught my eye, didn't see the geometry or number theory one.

So 40C5?

For my math classes, I kind of just cram the knowledge in my head an hour before tests so after the test it escapes my mind. I'm gonna have a lot of studying to do come exam time. Also, these questions never made much sense to me logically, I'd just follow the formulas.

Give the others a go :) I very much disagree with your style xD
 

Tera Path

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Tfw you can barely do any of these because you can't math in English :'(
 

Tera Path

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Can't you search translations?

I did, now I'm even more confused.
Oh boy, looks like I'm gonna have to start from the bottom again if I don't want to fail my math exams in a week.
 
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