Evaluate a multi-step numeric expression: Compute S = √(16 + (9.5 × 0.0085 × 18.9) / (0.021 × 0.0017 × 1.9)).

Aptitude Square Root and Cube Root Difficulty: Medium
Choose an option
  • A
    150
  • B
    154
  • C
    158
  • D
    160
  • E
    169

Answer

Correct Answer: 150

Explanation

Introduction / Context: This evaluates a nested expression mixing decimals and a square root. Careful order of operations and fraction handling are key.

Given Data / Assumptions: S = √(16 + (9.5 × 0.0085 × 18.9) / (0.021 × 0.0017 × 1.9)).

Concept / Approach: Compute the numerator and denominator separately, simplify the fraction, add 16, then take the square root.

Step-by-Step Solution: Numerator: 9.5 × 0.0085 × 18.9 = 1.526175.Denominator: 0.021 × 0.0017 × 1.9 = 0.00006783.Fraction = 1.526175 / 0.00006783 = 22500 exactly (since the decimals reduce to 22500).Inside root: 16 + 22500 = 22516.S = √22516 ≈ 150.05, which rounds to 150 among the given choices.

Verification / Alternative check: Quick check: since √22500 = 150 and our value is √22516, the answer must be just slightly above 150, so 150 is the nearest listed value.

Why Other Options Are Wrong: 154, 158, 160, 169 are far from the precise √22516 ≈ 150.05.

Common Pitfalls: Losing precision in decimal multiplication/division or misapplying square root to the fraction before summing with 16.

Final Answer: 150

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