Scale comparison via decimal division Evaluate: 50.8 ÷ 2540 = ?
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A2
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B.2
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C0.002
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D0.02
Answer
Correct Answer: 0.02
Explanation
Introduction / Context: This problem checks decimal division and recognition that multiplying a divisor by 0.02 can reproduce the dividend exactly. Spotting such proportional relationships speeds up calculations on tests.
Given Data / Assumptions:
- Compute 50.8 / 2540.
- No rounding is needed.
Concept / Approach: Look for a simple factor k such that 2540 * k = 50.8. Since 2540 * 0.02 = 50.8, the quotient is 0.02. Alternatively, scale both numbers to remove decimals and reduce the fraction.
Step-by-Step Solution:Test k = 0.02 ⇒ 2540 * 0.02 = 50.8.Hence 50.8 / 2540 = 0.02 directly.
Verification / Alternative check: As a fraction: 50.8/2540 = 508/25400 = divide by 254 ⇒ 2/100 = 0.02. The simplification confirms the same result.
Why Other Options Are Wrong:2, 0.2, 0.002: These correspond to multipliers that yield 5080, 508, or 5.08 when applied to 2540, not 50.8.
Common Pitfalls: Dropping or adding a zero when scaling; mistaking 0.2 for 0.02. Verify by multiplying back: divisor * quotient should equal dividend exactly.
Final Answer: 0.02