Question 1072336: 1. 1000 tickets are sold for a charity lottery at $5 each. 3 numbers are drawn out at random to receive 1st, 2nd, 3rd place prizes of $2000, $1000, and $500 respectively. (Like 124, 321, & 996). What is the mean (expectation) from such a drawing?
2. A fair coin is flipped 6 times. What is is the probability of getting at least 2 heads? First figure out how many are in the sample space.
3. In a club there are 6 men & 8 women. A committee of four is to be chosen.
a.) how many possible committees are there?
b.) how many possible committees are there which have 2 men & 2 women?
4. A shipment of 100 DVD's has 5 which are defective. If you pick 2 at random (do not replace), what is the probability that they are all good (non defective)?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 1. 1000 tickets are sold for a charity lottery at $5 each. 3 numbers are drawn out at random to receive 1st, 2nd, 3rd place prizes of $2000, $1000, and $500 respectively. (Like 124, 321, & 996). What is the mean (expectation) from such a drawing?
Random "winnings":: 1995......995....495....-5
Probability:::::::: 1/1000...1/1000..1/100..997/1000
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E(x) = [1995 + 995 + 495 - 5*997]/1000 = -$1.50
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2. A fair coin is flipped 6 times. What is is the probability of getting at least 2 heads? First figure out how many are in the sample space.
P(2<= x <=6) = 1 - binomcdf(6,0.5,1) = 0.8906
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3. In a club there are 6 men & 8 women. A committee of four is to be chosen.
a.) how many possible committees are there?:: 14C4 = 1001
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b.) how many possible committees are there which have 2 men & 2 women?
Ans: [6C2*8C2]/14C4 = [15*28]/1001 = 0.4196
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4. A shipment of 100 DVD's has 5 which are defective. If you pick 2 at random (do not replace), what is the probability that they are all good (non defective)?
And: 95C2/100C2 = 0.9020
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Cheers,
Stan H.
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