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Maths problems!


Guest DX's Birfday! - 7 Nov&#3

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Guest DX's Birfday! - 7 Nov&#3

Ok, I'm going to take some maths problems and see if you can resolve them! First to correctly answer the problem wins a prize!

 

This one was taken from my yesterday's Math test!

Maths Test - 9th grade

7th December 2006

 

2) Of 24 students of the 9º2 class, 20 have a dog and twelve have a cat.

Every student has at least one of these animals.

Calculate the probability of, choosing a random student he having:

a)the two animals

b)only a cat

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You do that random tree diagram, where you do branches off with probability of something happening or not happening. For a )...

 

abo7.gif

 

For b )...

 

baz8.gif

 

I know they're not simplified down, but since it's nearing midnight and I don't have a calculator to hand... it's kind of obvious why.

 

But is that right?

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Guest DX's Birfday! - 7 Nov&#3

Sorry, all are wrong! Where did you get those numbers from, Matt?!!!! I didn't know animals could be divided into fractions, poor them!

 

Matt, I think you are confounding this with the "with reposition" and "without reposition" cases.

 

mathsprobsolution.jpg

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Guest Merry HBK Xmas!
I think its a trick question, you asked for the probablity, which means it is either in fraction form or like 1:4??

 

No, there's no trick in it. This question is not to answer in a form of fraction. Informally, probable is one of several words applied to uncertain events or knowledge, being closely related in meaning to likely, risky, hazardous, and doubtful. Chance, odds, and bet are other words expressing similar notions. Just as the theory of mechanics assigns precise definitions to such everyday terms as work and force, the theory of probability attempts to quantify the notion of probable. Probability always lies between 0 and 1. If probability is equal to 1 then that event is certain to happen and if the probability is 0 then that event will never occur.

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Guest Merry HBK Xmas!
That's easy

 

x=-4/3, y=26/3

 

 

By the way, are the 2 answers of your first problem 5/12 and 1/12 respectively?

 

CORRECT! Although you didn't need a denominator for y, because both have the same common deno. which is 3. And no, the solution is above. Remember that -3 denominator is also negative on x.

 

Your welcome! The next problem will be about Triangles!

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Triangles? is he refering to geometery? With all the angles of the shapes and stuff u figure out. Zomg if it is I ACED thatt on my test :D .

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Woohoo thanks hehehe. But i learned that in september hopefully i still hve my skills :evil: . Zomg have anyone learnd about parabolas?

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