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In how many ways can the digits in the number 9,128,821 be​ arranged?

User Nzy
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Final answer:

There are 1120 different ways to arrange the digits in the number 9,128,821. This is calculated using the permutation formula for a multiset, taking into account the repetitions of '2' and '8'.

Step-by-step explanation:

To determine the number of ways the digits in the number 9,128,821 can be arranged, we have to consider that some digits are repeated. The number has a total of 8 digits consisting of one '9', one '1', three '2's, and three '8's. To calculate the total number of arrangements, we use the formula for permutations of a multiset, which is the factorial of the total number of digits divided by the product of the factorials of the counts of each unique digit.

The formula for this would be:

Arrangement = \( \frac{8!}{3! \times 3!} \)

Calculating this, it yields:

Arrangement = \( \frac{8 \times 7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1}{(3 \times 2 \times 1) \times (3 \times 2 \times 1)} \) = \( \frac{40320}{36} \) = 1120

Therefore, there are 1120 different ways to arrange the digits in the number 9,128,821.

User Borislav
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