$$2\frac{1}{4} + 1\frac{1}{3} - 4\frac{1}{2} = x$$
Aptitude
Simplification
Difficulty: Easy
Choose an option
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A$-1\frac{1}{12}$
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B$\frac{11}{12}$
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C$-\frac{11}{12}$
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D$1\frac{1}{12}$
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ENone of these
Answer
Correct Answer: $-\frac{11}{12}$
Explanation
### Concept & Strategy
This problem involves addition and subtraction of mixed fractions.
The fastest and most error-free method is to completely separate the integer (whole number) parts from the fractional parts. Calculate them independently, and then combine the final results.
### Step-by-Step Solution
* **Step 1:** Separate the expression into whole numbers and fractions.
Whole numbers: $(2 + 1 - 4)$
Fractions: $(\frac{1}{4} + \frac{1}{3} - \frac{1}{2})$
* **Step 2:** Solve the whole number portion.
$2 + 1 - 4 = -1$
* **Step 3:** Solve the fraction portion by finding a common denominator.
The Lowest Common Multiple (LCM) of 4, 3, and 2 is 12.
$\frac{1 \times 3}{12} + \frac{1 \times 4}{12} - \frac{1 \times 6}{12}$
$\frac{3 + 4 - 6}{12} = \frac{1}{12}$
* **Step 4:** Combine the whole number and fraction results.
Result $= -1 + \frac{1}{12}$
* **Step 5:** Simplify into a final single fraction.
$-1 + \frac{1}{12} = \frac{-12 + 1}{12} = -\frac{11}{12}$
### Exam Strategy & Shortcut
Avoid converting mixed fractions into improper fractions (e.g., $2\frac{1}{4} \rightarrow \frac{9}{4}$) when the whole numbers are small. Converting to improper fractions inflates the numerators and makes finding common denominators mathematically heavier and slower. The split method (Whole + Fraction) takes seconds and keeps numbers small.
### Common Pitfall
A frequent mistake is mishandling the negative sign in the final combination step. A student might calculate $-1$ and $\frac{1}{12}$, and incorrectly write the answer as $-1\frac{1}{12}$. Remember that $-1 + \frac{1}{12}$ means you are moving from -1 back towards zero on the number line, resulting in $-\frac{11}{12}$.
### Final Answer
**Therefore, the correct answer is -\frac{11}{12}.**