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Use the permutation formula to solve the problem when n=9 and r=7.

P(9,7)=9/(9-7)
a. 25,920
b. 90,720
c. 181,440
d. 362,880

User StingyJack
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1 Answer

4 votes

Final answer:

The solution to the permutation problem P(9,7) using the formula P(n, r) = n! / (n - r)! is 362,880. Hence, the correct answer is option d.

Step-by-step explanation:

An arrangement of objects in a specific order is called a permutation. Here, the components or members of sets are arranged in a linear or sequential order. The student's question relates to the use of the permutation formula to solve a problem where the number of items n is 9 and the number of positions r is 7.

The permutation formula is represented as P(n, r) = n! / (n - r)!, where '!' denotes factorial, which is the product of an integer and all the integers below it down to 1.

Using the permutation formula for P(9, 7), we calculate 9! / (9 - 7)!. This simplifies to 9! / 2!, which equals 9 x 8 x 7 x 6 x 5 x 4 x 3 / (2 x 1). The answer, therefore, is 362,880. This corresponds to option d (362,880).

User Magnilex
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