Question 857515: a drawer has 6 red socks and 4 white socks
if you draw 2 what is the probability of drawing a match
if 3 are drawn what is the probability of all 3 being the same color?
if 3 are drawn what is the probability of a match?
what is the probability of drawing all one color after 4 draws?
In a make up quiz a student is faced with a true false quiz with 6 questions. she has to guess at every question. Assuming that she has a 50% chance at each question what is the probability that she will answer at least 4 questions correctly?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! a drawer has 6 red socks and 4 white socks
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# of pairs of red: 6C2 = 15
# of pairs of white: 4C2 = 6
# of random pairs: 10C2 = 45
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if you draw 2 what is the probability of drawing a match:: 21/45
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if 3 are drawn what is the probability of all 3 being the same color?
[6C3 + 4C3]/10C3 = [20+4]/120 = 24/120 = 1/5
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if 3 are drawn what is the probability of a match
Assuming "a match" means rrw or rww
# of ways to succeed: [15*4+6*6]/10C3 = 66/120 = 33/60 = 11/20
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what is the probability of drawing all one color after 4 draws?
[6C4+ 4C4]/10C4 = [15+4]/210 = 19/210
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In a make up quiz a student is faced with a true false quiz with 6 questions. she has to guess at every question. Assuming that she has a 50% chance at each question what is the probability that she will answer at least 4 questions correctly?
P(4<= x <=6) = 1 - P(0<= x <=3) = 1 - binomcdf(6,0.5,3) = 0.6563
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Cheers,
Stan H.
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