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Question

Mathematics Question on permutations and combinations

Let α=(4!)!(4!)3!\alpha = \frac{(4!)!}{(4!)^{3!}} and β=(5!)!(5!)4!\beta = \frac{(5!)!}{(5!)^{4!}}. Then:

A

αN\alpha \in \mathbb{N} and βN\beta \notin \mathbb{N}

B

αN\alpha \notin \mathbb{N} and βN\beta \in \mathbb{N}

C

αN\alpha \in \mathbb{N} and βN\beta \in \mathbb{N}

D

αN\alpha \notin \mathbb{N} and βN\beta \notin \mathbb{N}

Answer

αN\alpha \in \mathbb{N} and βN\beta \in \mathbb{N}

Explanation

Solution

Given:
α=(4!)6(4!)66!=24!(4!)66!,β=(5!)24(5!)2424!=120!(5!)2424!.\alpha = \frac{(4!)^6}{(4!)^6 \cdot 6!} = \frac{24!}{(4!)^6 \cdot 6!}, \quad \beta = \frac{(5!)^{24}}{(5!)^{24} \cdot 24!} = \frac{120!}{(5!)^{24} \cdot 24!}.

Analyzing α\alpha:
Consider dividing 24 distinct objects into 6 groups of 4 objects each. The number of ways to form these groups is given by:
α=24!(4!)66!.\alpha = \frac{24!}{(4!)^6 \cdot 6!}.

Since this is a valid combinatorial expression representing the number of ways to arrange groups, αN\alpha \in \mathbb{N} (i.e., it is a natural number).

Analyzing β\beta:
Consider dividing 120 distinct objects into 24 groups of 5 objects each. The number of ways to form these groups is given by:
β=120!(5!)2424!.\beta = \frac{120!}{(5!)^{24} \cdot 24!}.

This is also a valid combinatorial expression, implying that βN\beta \in \mathbb{N}.

Conclusion:
Therefore, both α\alpha and β\beta are natural numbers.

The Correct answer is: αN\alpha \in \mathbb{N} and βN\beta \in \mathbb{N}