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# Probability:Find X watch

1. Any ideas or starting points?
2. (Original post by Y11_Maths)
Any ideas or starting points?
What's the probability of landing on each number??

Then, what are the possible combinations to get a total score of 4?
3. So there are 4 combinations that would get a total score of 4: 2&2 2&2 1&3 3&1
How do I work out the probability of landing on each number? P(1) is x/360?
4. (Original post by Y11_Maths)
So there are 4 combinations that would get a total score of 4: 2&2 2&2 1&3 3&1
How do I work out the probability of landing on each number? P(1) is x/360?
No there are only 3. You don't count 2&2 twice since different order produces the same branch if you consider the tree diagram.

And yes, x/360 is the probability of landing on 1 on a given spin
5. (Original post by RDKGames)
No there are only 3. You don't count 2&2 twice since different order produces the same branch if you consider the tree diagram.

And yes, x/360 is the probability of landing on 1 on a given spin
Ok so I know the probability of getting a 1 or 2 but how do I do it for 3? Is it 360-3x all divided by 360? But that equals 1-3x/360 no?
6. (Original post by Y11_Maths)
Ok so I know the probability of getting a 1 or 2 but how do I do it for 3? Is it 360-3x all divided by 360? But that equals 1-3x/360 no?
Yes, that's right.
7. (Original post by RDKGames)
Yes, that's right.
Am I on the right track?
8. (Original post by Y11_Maths)
Am I on the right track?
Probabilities are multiplied, THEN all 3 are added together to give 16/81
9. (Original post by RDKGames)
Probabilities are multiplied, THEN all 3 are added together to give 16/81
Oh right I think I get it
10. (Original post by RDKGames)
Probabilities are multiplied, THEN all 3 are added together to give 16/81
Is this correct?
11. (Original post by Y11_Maths)
Is this correct?
No,
12. (Original post by RDKGames)
No,
I’m on the app so this code makes no sense to me
13. (Original post by Y11_Maths)
I’m on the app so this code makes no sense to me
I recommend you use a computer when asking for maths help because 'this code stuff' is very useful.

My post:

14. (Original post by RDKGames)
I recommend you use a computer when asking for maths help because 'this code stuff' is very useful.

My post:

Ok noted for future references, and I see where I went wrong thanks. Is everything else I did correct though? Solve for x through a quadratic?
15. (Original post by Y11_Maths)
Ok noted for future references, and I see where I went wrong thanks. Is everything else I did correct though? Solve for x through a quadratic?
The actual method is fine, yes, though there are silly errors like not squaring 360 on the denominator on the 2+2 case
16. (Original post by RDKGames)
The actual method is fine, yes, though there are silly errors like not squaring 360 on the denominator on the 2+2 case
I did it on my calculator then got distracted 😂. Thanks for the help mate
17. (Original post by RDKGames)
The actual method is fine, yes, though there are silly errors like not squaring 360 on the denominator on the 2+2 case
I feel like I’ve gone wrong because I don’t think x can be 40 degrees can it?
18. (Original post by Y11_Maths)
I feel like I’ve gone wrong because I don’t think x can be 40 degrees can it?
Why can't it...?

19. (Original post by RDKGames)
Why can't it...?

40*3= 120 which is less than 180 degrees. I just thought it was inaccurate, but it probably isn’t drawn accurately tbf
20. I got the answer as x=32.60291625 degrees

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Updated: February 11, 2018
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