The expression $$\frac{3\frac{1}{4} - \frac{4}{5} \text{ of } \frac{5}{6}}{4\frac{1}{3} \div \frac{1}{5} - \left(\frac{3}{10} + 21\frac{1}{5}\right)}$$ is equal to
Aptitude
Simplification
Difficulty: Medium
Choose an option
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A15(1/2)
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B12(1/4)
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C14
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DNone of these
Answer
Correct Answer: 15(1/2)
Explanation
### Concept & Formula
Simplify components methodically by applying the **BODMAS** sequence. Convert mixed fractions to improper fractions at the start.
### Step-by-Step Solution
* **Step 1: Simplify the Numerator**
$$\text{Numerator} = 3\frac{1}{4} - \frac{4}{5} \text{ of } \frac{5}{6}$$
Convert to improper fraction: $3\frac{1}{4} = \frac{13}{4}$
Evaluate the 'of' operation:
$$\frac{4}{5} \times \frac{5}{6} = \frac{4}{6} = \frac{2}{3}$$
Subtract the terms:
$$\frac{13}{4} - \frac{2}{3} = \frac{39 - 8}{12} = \frac{31}{12}$$
* **Step 2: Simplify the Denominator**
$$\text{Denominator} = 4\frac{1}{3} \div \frac{1}{5} - \left(\frac{3}{10} + 21\frac{1}{5}\right)$$
First term of denominator:
$$\frac{13}{3} \div \frac{1}{5} = \frac{13}{3} \times 5 = \frac{65}{3}$$
Bracket term of denominator:
$$\frac{3}{10} + \frac{106}{5} = \frac{3 + 212}{10} = \frac{215}{10} = \frac{43}{2}$$
Combine the denominator terms:
$$\frac{65}{3} - \frac{43}{2} = \frac{130 - 129}{6} = \frac{1}{6}$$
* **Step 3: Compute the Final Value**
$$\text{Value} = \frac{\frac{31}{12}}{\frac{1}{6}} = \frac{31}{12} \times 6 = \frac{31}{2} = 15\frac{1}{2}$$
### Exam Strategy & Shortcut
When resolving fractions with simple denominators like 2 and 3 in the final subtraction steps, look for quick subtraction setups (e.g., $130 - 129 = 1$), which simplifies the entire denominator into a single unit fraction ($\frac{1}{6}$) instantly.
### Common Pitfall
Forgetting to find a common denominator when adding numbers inside the parentheses ($\frac{3}{10} + \frac{106}{5}$) often introduces early calculation errors.
### Final Answer
**Therefore, the correct answer is 15(1/2).**