Clarify grouping and evaluate: Compute √(0.16 / 0.4) and choose the correct decimal approximation.
Aptitude
Square Root and Cube Root
Difficulty: Easy
Choose an option
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A0.2
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B0.02
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C0.63
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D2√5/5
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E1
Answer
Correct Answer: 0.63
Explanation
Introduction / Context:The original text can be ambiguous; consistent with the options, interpret it as √(0.16 / 0.4). We simplify the fraction first, then take the square root and compare to the listed choices.
Given Data / Assumptions:
- Evaluate √(0.16 / 0.4).
- Use principal (positive) square roots.
Concept / Approach:Simplify the ratio inside the root: 0.16 / 0.4 = 16/40 = 2/5 = 0.4. Then take √0.4 and express as a decimal or simple surd if needed.
Step-by-Step Solution:
0.16 / 0.4 = 0.4.√0.4 = √(4/10) = √(2/5) = (√10)/5 ≈ 0.632455...Rounded to two decimals, this is about 0.63.Verification / Alternative check:Square 0.63 ≈ 0.3969, close to 0.4; using exact (√10)/5 squared is exactly 0.4.
Why Other Options Are Wrong:
- 0.2 and 0.02 are too small.
- 2√5/5 ≈ 0.894 is too large.
- 1 is the value of √0.16/0.4 if mis-grouped; with correct grouping the value is ≈ 0.632.
Common Pitfalls:Ignoring parentheses and computing (√0.16)/0.4 = 1; the intended grouped form avoids this ambiguity.
Final Answer:0.63