Help solve simple math problem.

Discussion in 'General Off-Topic Chat' started by Devante, May 20, 2011.

  1. Devante
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    Devante Crescent fresh at best.

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    Hey guys.

    Sounds dumb but how do I find the probability of the following question?

    A class has 32 students. Out of that class, 4 will fail.
    Rudy is in this class.
    What is the probability of Rudy failing?

    I keep coming up with 1/8 but I think I'm missing a step.
     
  2. Recorderdude

    Recorderdude Musician, Animator, Buffoon.

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    4/32

    divide both by four

    1/8

    it's that simple. 1/8 will fail and he has a 1/8 chance of failing. this could also be expressed as .125, 12.5% or 1:8.
     
  3. s4mid4re

    s4mid4re  

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    to be a little clearer, 1/8 = 1÷8
    if you solve 1÷8, it becomes .125 (you can also solve by 4÷32 and get the same answer)
    move the decimal 2 places to the right and you get the percentage (12.5%)
    1:8 (one to eight) is the simplified ratio form. just think of the colon as a division sign.
     
  4. Nathan Drake

    Nathan Drake Obligations fulfilled, now I depart.

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    I wanna say 1/256. There is a 4/32 chance that four of the students will fail. There is also a 1/32 chance that the student could be Rudy.

    To account for this, you have to set it up as follows:
    (4/32)(1/32) = 1/256 chance that the failed student is Ricky

    I wanna go ahead and say this is wrong though. I could say how to do this perfectly if I felt like pulling out my notes from my mini-probability unit in Pre-Calculus earlier this year. Instead of people, it was dice. It was something like the odds of it being a number 1 - 3 in six rolls, and how many times the number 2 would show up and crap like that.

    Take my answer with a grain of salt, or a shaker, or a factory full. [​IMG]
     
  5. s4mid4re

    s4mid4re  

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    I don't think that's what's being asked. If my interpretation is correct, this would be a variant of the question:
    One of the 4 students that are failing can be Rudy, out of a total of 32 students. What is the probability that Rudy is 1 of the 4 students?
     
  6. SinHarvest24

    SinHarvest24 Shiroyasha

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    you were just over-thinking things ^

    The answer you got is correct. So is everyone else here.
     
  7. Devante
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    Devante Crescent fresh at best.

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    Thanks guys. :>
     
  8. wasim

    wasim ♫ Music addict ♫

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    looks like there are many maths genius here

    ( solution for my homeworks is here [​IMG] )
     
  9. CarbonX13

    CarbonX13 GBAtemp 台灣人

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    Um... this really takes nothing more than what you learn in maybe grade 4 elementary school... [​IMG]
     
  10. wasim

    wasim ♫ Music addict ♫

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    i learned this in 6th grade
     
  11. Chhotu uttam

    Chhotu uttam DOH HO HO HO

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    but i learned it in 9th grade.(joking)
     
  12. Nathan Drake

    Nathan Drake Obligations fulfilled, now I depart.

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    I didn't start to learn how to add, subtract, multiply, and divide fractions until pre-algebra. Through elementary school, it was pretty much all basic shit and memorizing stuff you'll never need to memorize again.
     
  13. chris888222

    chris888222 GBAtemp's Flygon Fan

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    Darn my math sucks :/
     
  14. mcp2

    mcp2 GBAtemp Advanced Fan

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    UK blud dun kno
    Here ya go

    [​IMG]

    [​IMG]
     
  15. SamAsh07

    SamAsh07 GBAtemp Addict

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    ^ You forgot to state - use magnets for faster calculation AND Math question writing teachers will go bankrupt.
     
  16. CarbonX13

    CarbonX13 GBAtemp 台灣人

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    Maybe it's the States then. I learned how to divide, multiply, add, and subtract factions in grade 4, and BEDMAS and such by grade 5.
     
  17. Devante
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    Devante Crescent fresh at best.

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    P.S. I was drunk when I made this thread. ;>