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Anonymous
Anonymous asked in Science & MathematicsMathematics · 2 decades ago

Math probabilty help?

From a group of five men and four women, determine the probabilty that these would form:

B. exactly 3 women

D. no women

F. at least 3 women

Update:

oo sorry, they have to form a group of 5 ppl.

6 Answers

Relevance
  • 2 decades ago
    Favorite Answer

    Count the total number of groups:

    9 choose 5 = 9*8*7*6/(4*3*2*1) = 9*2*7 = 126.

    b) Count the number of groups where 3 women where chosen and 2 men.

    (4 choose 3) * (5 choose 2) = 4 * 10 = 40.

    The prob that a random committee has exactly 3 women = 40/126

    c) If there were no women then the number of ways this can happen is:

    (4 choose 0) * (5 choose 5). As you could probably already see, there is only 1 way to have a committe of 5 men and 0 women. The prob = 1/126.

    f) >=3 women is the same as saying 3 or 4 women as 4 women is the most you can have.

    (4 choose 3)*(5 choose 2) + (4 choose 4) * (5 choose 1)=

    4*10 + 1*5 = 45. Prob = 45/126.

  • 2 decades ago

    Your question is missing a very important part to determine probability.

    How many do you want in your group? If you don't give that information, the question is open to interpretation.

    I'm going to do a little explaining, and try to solve the problem yourself.

    1. Separate the problem into 2 sets that don't intersect (what is in one set doesn't exist in the other)

    For this problem the 2 sets are obviously Men and Women. If you're one, you aren't considered in the other.

    2. Determine how many of each set you want. Both sets should have a number even if it's zero.

    3. Determine if order is important in how a choice is made. If it's important, use Permutations, if not use Combinations.

    Say you want a group of 4 people where exactly 3 are women.

    Separate into groups.

    1. Men, Women.

    2. How many we want from each group. To get exactly 3 women, we want exactly 1 man.

    Men: 1, Women: 3

    3. Order of selection is not important.

    use Combination.

    C(5,1) * C(4,3) will be the numerator of your probability.

    Where

    C(5,1) Means I have 5 men total, and I want exactly 1.

    C(4,3) Means 1 have 4 women total and I want exactly 3.

    We multiple these two to get the total possible.

    The denominator is simply group everything together. we want 4 people out of 9

    C(9,4)

    Try doing the other two yourself.

  • Anonymous
    2 decades ago

    Part of your question is missing. Read it again. A group of five men and four women cannot suddenly "become" any of the options you give without first picking a number of them at random. How many was it you were supposed to pick?

  • 2 decades ago

    in a 5 men and 4 women.

    if 3 person is outcome then;

    I-1 man and 2 women,

    II-2 men and 1 woman,

    III-at least 3 men.

    IV-at least 3 women.

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  • Anonymous
    2 decades ago

    i LOVE the kings. lol srry they're just awesome. do u kno fool?

  • Anonymous
    2 decades ago

    F

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