Evaluate [(0.1 × 0.1 × 0.1) + (0.02 × 0.02 × 0.02)] ÷ [(0.2 × 0.2 × 0.2) + (0.04 × 0.04 × 0.04)].
Aptitude
Decimal Fraction
Difficulty: Medium
Choose an option
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A1/4
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B1/6
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C1/8
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D1/10
Answer
Correct Answer: 1/8
Explanation
Problem restatementCompute the ratio of the two sums of cubes of small decimals.
Given data
- Left sum: 0.13 + 0.023
- Right sum: 0.23 + 0.043
Concept/ApproachEvaluate each cube exactly (powers of 10 are easy), add, then simplify the fraction by noticing a common factor.
Step-by-step calculationLeft = 0.001 + 0.000008 = 0.001008Right = 0.008 + 0.000064 = 0.008064Ratio = 0.001008 ÷ 0.008064 = 1008 ÷ 8064 = 1/8
Verification/AlternativeBoth numerator and denominator are multiples of 1008: 8064 = 8 × 1008.
Common pitfallsRounding intermediate cubes (e.g., treating 0.023 as 0.00002) which distorts the ratio.
Final Answer1/8