Elijah forgot his pass code for a certain website. He knows it is made up of 5 digits and no digit can be repeated. If he randomly chooses 5 different digits, what is the probability that he chooses his pass code?

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Elijah forgot his pass code for a certain website. He knows it is made up of 5 digits and no digit can be repeated. If he randomly chooses 5 different digits, what is the probability that he chooses his pass code?

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Answer 1 · 2017-02-20T03:03:42

The chances are $\frac{1}{30, 240}$ $1/(30,240)$ .

Explanation:

Use the permutation formula, as order matters, to determine the number of permutations that are possible. Call the number of permutations $P$ $P$ . There are 10 possible digits to choose from, and he needs to choose $5$ $5$ different digits, so $P$ $P$ is given by

$P = \frac{n!}{(n - r)!}$ $P = (n!)/((n - r)!)$

$P = \frac{10!}{(10 - 5)!}$ $P = (10!)/((10 - 5)!)$

$P = 30240$ $P = 30240$

If he randomly chooses one set of $5$ $5$ digits, than his chances that he chooses the correct pass code is $\frac{1}{30, 240}$ $1/(30,240)$

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Elijah forgot his pass code for a certain website. He knows it is made up of 5 digits and no digit can be repeated. If he randomly chooses 5 different digits, what is the probability that he chooses his pass code?

1 Answer

Explanation:

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