$\sqrt{110\frac{1}{4}} = x$
Aptitude
Square Root and Cube Root
Difficulty: Easy
Choose an option
-
A10.25
-
B10.5
-
C11.5
-
D19.5
Answer
Correct Answer: 10.5
Explanation
### Concept & Strategy
Convert the mixed fraction into an improper fraction, take the square root of the numerator and denominator independently, and then convert back into decimal format.
Fraction conversion identity:
$$ \sqrt{\frac{a}{b}} = \frac{\sqrt{a}}{\sqrt{b}} $$
### Step-by-Step Solution
- **Step 1: Convert the mixed fraction to an improper fraction.**
- Multiply the integer by the denominator and add the numerator: $110 \times 4 + 1 = 440 + 1 = 441$.
- The expression becomes: $\sqrt{\frac{441}{4}}$
- **Step 2: Extract the square roots.**
- Split the radical: $\frac{\sqrt{441}}{\sqrt{4}}$
- We know $\sqrt{441} = 21$ and $\sqrt{4} = 2$.
- Result: $\frac{21}{2}$
- **Step 3: Convert the fraction to a decimal value.**
- $\frac{21}{2} = 10.5$
### Exam Strategy & Shortcut
Alternatively, express the value directly as a decimal from the start: $\sqrt{110\frac{1}{4}} = \sqrt{110.25}$.
We know that $10^2 = 100$ and $11^2 = 121$, so the answer must be between $10$ and $11$.
Since the number ends in $.25$, its square root must end in $.5$. This points straight to $10.5$.
### Common Pitfall
Mistakenly picking option (a) $10.25$ because the original question had a $\frac{1}{4}$ fractional component, assuming that the root splits directly onto the component parts. Never split a radical across individual terms of an addition or mixed fraction format.
### Final Answer
Therefore, the correct answer is 10.5.