1) A five-digit number is created using the digits 1-5 each once. What is the probability that the number is odd? Express your answer as a common fraction.

2) The sum of the digits of a number is 9. What is the

probability that the number is prime?

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- Oct 2nd 2009, 10:37 AMsri340PROBABILITY problems help please
1) A five-digit number is created using the digits 1-5 each once. What is the probability that the number is odd? Express your answer as a common fraction.

2) The sum of the digits of a number is 9. What is the

probability that the number is prime?

- Oct 2nd 2009, 12:28 PMgalactus
#1:

$\displaystyle \frac{5^{4}\cdot 3}{5^{5}}=\frac{3}{5}$

As Plato pointed out, I made a mistake and overlooked your problem said, 'each digit appears once'. Instead of deleting it, let's just say this is the case where the digits repeat. - Oct 2nd 2009, 12:33 PMPlato
- Oct 2nd 2009, 12:48 PMgalactus
Oh, I overlooked that. (Angry)

Thanks.