If $\sqrt{24} = 4.899$, the value of $\sqrt{\frac{8}{3}}$ is
Aptitude
Square Root and Cube Root
Difficulty: Medium
Choose an option
-
A0.544
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B1.333
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C1.633
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D2.666
Answer
Correct Answer: 1.633
Explanation
### Concept & Formula
To utilize a given square root value, manipulate the fraction under the radical by multiplying the numerator and denominator by the same number to create the known value.
$$ \sqrt{\frac{a}{b}} = \sqrt{\frac{a \times k}{b \times k}} $$
### Step-by-Step Solution
Given: $\sqrt{24} = 4.899$
We need to find the value of $\sqrt{\frac{8}{3}}$.
Notice that the numerator $8$ can be turned into $24$ if multiplied by $3$. Multiply both the numerator and the denominator by $3$:
$\sqrt{\frac{8 \times 3}{3 \times 3}}$
Simplify the fraction inside the square root:
$\sqrt{\frac{24}{9}}$
Apply the square root to the numerator and denominator separately:
$\frac{\sqrt{24}}{\sqrt{9}}$
This simplifies to:
$\frac{\sqrt{24}}{3}$
Substitute the given value for $\sqrt{24}$:
$\frac{4.899}{3}$
Perform the division:
$4.899 \div 3 = 1.633$
### Exam Strategy & Shortcut
Look for relationships immediately. $8$ and $24$ are related by a factor of $3$. Multiply the fraction by $3/3$ mentally to get $24/9$. The square root of $9$ is $3$, so you just need to divide the given value by $3$. $4.8 / 3 = 1.6$. Only option (c) matches.
### Common Pitfall
Students often try to divide $8$ by $3$ to get $2.666...$ and then attempt to find the square root of $2.666...$ manually. This ignores the given information and guarantees a difficult calculation.
### Final Answer
Therefore, the correct answer is **1.633**.