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A is given a phone list containing 200 different phone
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06 Dec 2003, 17:26
06 Dec 2003, 17:26
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24.A is given a phone list containing 200 different phone
numbers. B is given the same phone list A and B are ask to call one phone
number at the same time.
a. What is the probability that A and B call the same number?
b. What is the probability that A and B call a specific number?
Is a different from b.
numbers. B is given the same phone list A and B are ask to call one phone
number at the same time.
a. What is the probability that A and B call the same number?
b. What is the probability that A and B call a specific number?
Is a different from b.
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Re: A is given a phone list containing 200 different phone
[#permalink]
06 Dec 2003, 21:32
06 Dec 2003, 21:32
Quote:
a. What is the probability that A and B call the same number?
1/200.
Quote:
b. What is the probability that A and B call a specific number?
the probability that A calls a specific number:1/200
the probability that B calls the same specific number: 1/200
1/40000 is the probability of both A and B calling the same, prespecified.
This might be confusing, but try to look at it this way, and assume the numbers are simply 1,2,3,4...200
A could call any of these numbers, so there's a 1/200 chance of A calling a specific number, say, #153
B could call any of these numbers, so there's a 1/200 chance of B calling a specific number, say, #153
1/40000 is the chance of A and B both calling #153.
but, the odds of A and B calling the same number (any number) is still 1/200.
I can try again if this makes no sense.
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Re: A is given a phone list containing 200 different phone
[#permalink]
07 Dec 2003, 05:50
07 Dec 2003, 05:50
stoolfi wrote:
Quote:
a. What is the probability that A and B call the same number?
1/200.
Quote:
b. What is the probability that A and B call a specific number?
the probability that A calls a specific number:1/200
the probability that B calls the same specific number: 1/200
1/40000 is the probability of both A and B calling the same, prespecified.
This might be confusing, but try to look at it this way, and assume the numbers are simply 1,2,3,4...200
A could call any of these numbers, so there's a 1/200 chance of A calling a specific number, say, #153
B could call any of these numbers, so there's a 1/200 chance of B calling a specific number, say, #153
1/40000 is the chance of A and B both calling #153.
but, the odds of A and B calling the same number (any number) is still 1/200.
I can try again if this makes no sense.
The easiest way to explain 1 is to say:
No matter what number A calls, there is a 1/200 chance that B will match it. Hence, the prob is 1/200.
