probability word problem help, please....

Ok, I have 3 word problems dealing with probability that I need help with. So here they are:(Wondering)

1.Suppose a contest offers $1,000 to the person who can guess the winning 4 digit number. How many possibilities are there?

2. Two marbles are drawn froma bag containing 6 white, 4 red, and 6 green marbles. Find the probability of both marbles being white.

3. Suppose there are 10 items on a true-false test. The person taking the test does not read the questions; he just answers each question randomly. What is the probability of his guessing all answers correctly?

Thanks in advance for any help!

Well number 2 is relatively easy you take the amount of white marbles 6 then put it over the total amount of marbles i.e 6+4+6 so u get 6/16(for the prob. that the first marble is white) then multiply that by 5/15(i.e. prob that second marble is white) then u get 17/24 for

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Originally Posted by JoanneMac

Ok, I have 3 word problems dealing with probability that I need help with. So here they are:(Wondering)

1.Suppose a contest offers $1,000 to the person who can guess the winning 4 digit number. How many possibilities are there?

2. Two marbles are drawn froma bag containing 6 white, 4 red, and 6 green marbles. Find the probability of both marbles being white.

3. Suppose there are 10 items on a true-false test. The person taking the test does not read the questions; he just answers each question randomly. What is the probability of his guessing all answers correctly?

Thanks in advance for any help!

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Number three i believe that u multiply his chances of getting each question correct i.e he has 1/2 chance of getting number one corect then 1/2 chance of getting number two correct so u end up with 1/2x by itself 10 times or 1/2^10 and u get an answer of 1/1024

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Originally Posted by JoanneMac

Ok, I have 3 word problems dealing with probability that I need help with. So here they are:(Wondering)

1.Suppose a contest offers $1,000 to the person who can guess the winning 4 digit number. How many possibilities are there?

2. Two marbles are drawn froma bag containing 6 white, 4 red, and 6 green marbles. Find the probability of both marbles being white.

3. Suppose there are 10 items on a true-false test. The person taking the test does not read the questions; he just answers each question randomly. What is the probability of his guessing all answers correctly?

Thanks in advance for any help!

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i think number one is just that the amount of possibilities are 9999

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Originally Posted by adeshSB

i think number one is just that the amount of possibilities are 9999

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You mean(9)(9)(9)(9) = 9^4, right ....?

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Originally Posted by JoanneMac

[snip]

2. Two marbles are drawn froma bag containing 6 white, 4 red, and 6 green marbles. Find the probability of both marbles being white.

[snip]

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Drawing a tree diagram is always a good idea for these sorts of questions.

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Originally Posted by JoanneMac

Ok, I have 3 word problems dealing with probability that I need help with. So here they are:(Wondering)

1.Suppose a contest offers $1,000 to the person who can guess the winning 4 digit number. How many possibilities are there?

2. Two marbles are drawn froma bag containing 6 white, 4 red, and 6 green marbles. Find the probability of both marbles being white.

3. Suppose there are 10 items on a true-false test. The person taking the test does not read the questions; he just answers each question randomly. What is the probability of his guessing all answers correctly?

Thanks in advance for any help!

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3. The chance of getting any one question right is 50%, or 0.5.

The chance of getting all 10 right is (0.5)^10, or .0009765625. If we round this to .001, that means you have about one chance in a thousand of getting them all right, or 0.1%

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Originally Posted by TheMasterMind

3. The chance of getting any one question right is 50%, or 0.5.

The chance of getting all 10 right is (0.5)^10, or .0009765625. If we round this to .001, that means you have about one chance in a thousand of getting them all right, or 0.1%

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*Ahem* .... Which confirms reply #3 .....