$(0.05 \times 5 - 0.005 \times 5)$ equals
Aptitude
Decimal Fraction
Difficulty: Easy
Choose an option
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A0.0225
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B0.225
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C0.250
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D0.275
Answer
Correct Answer: 0.225
Explanation
Concept & Formula
This problem requires basic arithmetic operations following the order of operations (BODMAS/PEMDAS). Alternatively, you can use the distributive property of multiplication to factor out common terms and simplify the calculation:
$$a \times c - b \times c = c(a - b)$$
Step-by-Step Solution
**Method 1: Direct Calculation (BODMAS)**
* Perform the multiplications first:
$0.05 \times 5 = 0.25$
$0.005 \times 5 = 0.025$
* Subtract the second product from the first:
$0.25 - 0.025 = 0.225$
**Method 2: Factoring**
* Both terms are multiplied by 5, so factor it out:
$$5 \times (0.05 - 0.005)$$
* Perform the subtraction inside the parentheses:
$$5 \times 0.045$$
* Multiply by 5:
$$0.225$$
Exam Strategy & Shortcut
Using direct calculation is usually faster for simple multiples like 5. Think of money or simple fractions: $5 \times 5$ cents is $25$ cents ($0.25$). $5 \times 5$ tenths of a cent is $2.5$ cents ($0.025$). Aligning the decimals mentally: $0.250 - 0.025$ leaves $0.225$.
Common Pitfall
Misaligning the decimal points during subtraction is the primary error here. Students often calculate $0.25 - 0.025$ in their heads and mistakenly get $0.0225$ or $0.250$, forgetting to append a zero ($0.250$) to align the places properly before subtracting.
Final Answer
**Therefore, the correct answer is 0.225.**