Medium MCQ +4 / -1 PYQ · JEE Mains 2024

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

  1. A $\alpha \in \mathbf{N}$ and $\beta \in \mathbf{N}$ Correct answer
  2. B $\alpha \in \mathbf{N}$ and $\beta \notin \mathbf{N}$
  3. C $\alpha \notin \mathbf{N}$ and $\beta \in \mathbf{N}$
  4. D $\alpha \notin \mathbf{N}$ and $\beta \notin \mathbf{N}$

Solution

<p>$$\begin{aligned} & \alpha=\frac{(4 !) !}{(4 !)^{3 !}}, \beta=\frac{(5 !) !}{(5 !)^{4 !}} \\ & \alpha=\frac{(24) !}{(4 !)^6}, \beta=\frac{(120) !}{(5 !)^{24}} \end{aligned}$$</p> <p>Let 24 distinct objects are divided into 6 groups of 4 objects in each group.</p> <p>No. of ways of formation of group $=\frac{24 !}{(4 !)^6 .6 !} \in \mathrm{N}$<?p> <p>Similarly,</p> <p>Let 120 distinct objects are divided into 24 groups of 5 objects in each group.</p> <p>No. of ways of formation of groups</p> <p>$=\frac{(120) !}{(5 !)^{24} \cdot 24 !} \in \mathrm{N}$</p>

About this question

Subject: Mathematics · Chapter: Permutations and Combinations · Topic: Fundamental Counting Principle

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