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**Al-Allo****Member**- Registered: 2012-08-23
- Posts: 294

could you show me in details my error pls ?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,493

You are correct here, all three hitting:

0.4*0.3*0.8 because you computed three arrows being fired.

Here you are incorrect

0,4 * 0,3= 0,12 or 0,4*0,8= 0,32 or 0,3*0,8=0,24 you only fired 2 arrows what about the third? The one that missed?

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**Al-Allo****Member**- Registered: 2012-08-23
- Posts: 294

Ok, must I see it that that way

1-No one gets-2 persons don't get it-1 person don't get it- every one gets it- 2 persons gets it- 1 person gets it = 0

???

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,493

Here is how to see it. If you tree these that is when you see the errors quickly. I will give you another approach

h means hit and m means miss. There are 3 2 hits and 1 miss. Do you see them?

For instance Tom hits, Alice hits and Julie misses. To get the probability for that just fill in

Tom = h = .4

Alice = h = .3

Julie = m = .2

.4*.3*.2 = .024

You do the other 2 and add them up

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**Al-Allo****Member**- Registered: 2012-08-23
- Posts: 294

AH......... ok, Sh... I should have done a drawing to help me see it. Ok, now, I know how to finish do it.

Here's, in the ordrer of the diagramm, the probabilities :

0.096+0.024+0.224+0.056+0,144+0,036+0,336+0,084=1

GOOD!

Thank you bobbym, I've learned from it !

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,493

Hi;

Did you calculate using the m's too?

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**Al-Allo****Member**- Registered: 2012-08-23
- Posts: 294

YEs, I've included the m's in the equation above. ALso, I got 0,392 for two persons hitting !

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,493

Very good! These problems can be tricky. I got the wrong answer too. You have to be careful. Now you can figure out 0,1,2,3 easily.]

See you later, I have to go.

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**Al-Allo****Member**- Registered: 2012-08-23
- Posts: 294

Ok, bye and thank you again. If it happens again, I'll remember to do a drawing like yours !

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,493

Hi;

You are a fast learner.

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**Angie Pop****Member**- Registered: 2013-07-14
- Posts: 3

I have just had a bit of look at these particular posts regarding "A little question on Probability". I was on the understanding that this forum was for Maths is Fun for Kids from Kindergarten to Year 12, just looking at these particular posts I don't se how this forum would assist me if I was to ask about "Probability - Chance and Data" - for Kids

Thank you

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,493

Hi Angie Pop;

Welcome to the forum.

I don't se how this forum would assist me if I was to ask about "Probability - Chance and Data" - for Kids

Hmmm, might be worth a shot to post your question and see what the tooth fairy brings.

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**Angie Pop****Member**- Registered: 2013-07-14
- Posts: 3

That is a fair response, quite amazed at what I looked at in previous posts, is all, the course that I am doing is for Kids in Early Primary to Mid School and Upper Primary, just looking at the Maths is Fun website, seems more simplistic

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,493

Hi;

The MIF site has tons of stuff on probability.

http://www.mathsisfun.com/data/probability.html

http://www.mathsisfun.com/probability_line.html

When the kids have a question about any of it, that is when it is time to come in here.

Then they can learn from Yoda, the Jedi master who instructed me.

I never thought I would get a chance to use that quote from "The Empire Strikes Back!"

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

**Online**