Let $a, b, c$ and $d$ be positive real numbers such that $a+b+c+d=11$. If the maximum value of $a^{5} b^{3} c^{2} d$ is $3750 \beta$, then the value of $\beta$ is
Solution
Given that $a+b+c+d=11$ and the maximum value of $a^5 b^3 c^2 d$ is $3750\beta$, you assumed the numbers to be $$\frac{a}{5}, \frac{a}{5}, \frac{a}{5}, \frac{a}{5}, \frac{a}{5}, \frac{b}{3}, \frac{b}{3}, \frac{b}{3}, \frac{c}{2}, \frac{c}{2}, d$$.
<br/><br/>Applying the AM-GM inequality:
<br/><br/>$$\frac{\frac{a}{5}+\frac{a}{5}+\frac{a}{5}+\frac{a}{5}+\frac{a}{5}+\frac{b}{3}+\frac{b}{3}+\frac{b}{3}+\frac{c}{2}+\frac{c}{2}+d}{11} \geq\left(\frac{\left(a^5 b^3 c^2 d\right)}{5^5 3^3 2^2 1}\right)^{\frac{1}{11}}$$
<br/><br/>Since $a+b+c+d=11$, we have:
<br/><br/>$$1 \geq\left(\frac{\left(a^5 b^3 c^2 d\right)}{5^5 3^3 2^2 1}\right)^{\frac{1}{11}}$$
<br/><br/>Now, raising both sides to the power of 11:
<br/><br/>$1^{11} \geq \frac{a^5 b^3 c^2 d}{5^5 3^3 2^2 1}$
<br/><br/>From the given information, we know that $a^5 b^3 c^2 d \geq 3750\beta$:
<br/><br/>$5^5 3^3 2^2 \geq 3750\beta$
<br/><br/>Now, we can solve for $\beta$:
<br/><br/>$\beta \leq \frac{1}{3750} \cdot 5^5 3^3 2^2$
<br/><br/>Since we are looking for the maximum value of $\beta$, we take the equality case:
<br/><br/>$\beta = \frac{1}{3750} \cdot 5^5 3^3 2^2$
<br/><br/>Calculating the value, we find that:
<br/><br/>$\beta = 90$
<br/><br/>So, the value of $\beta$ is 90.
About this question
Subject: Mathematics · Chapter: Sequences and Series · Topic: Arithmetic Progression
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