Evaluate an exact fractional square root: Compute √(36.1 / 102.4) and express it as a simplified fraction.
Aptitude
Square Root and Cube Root
Difficulty: Easy
Choose an option
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A29/32
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B19/72
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C19/32
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D29/62
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ENone of these
Answer
Correct Answer: 19/32
Explanation
Introduction / Context:Converting decimals to exact fractional forms often reveals perfect-square structure. Here, we simplify inside the radical first, then take the square root.
Given Data / Assumptions:
- Expression: √(36.1 / 102.4).
- Decimals are exact terminating decimals convertible to fractions.
Concept / Approach:Multiply numerator and denominator to remove decimals and look for squares. Note that 36.1/102.4 = 361/1024 after scaling by a factor of 10 in numerator and denominator.
Step-by-Step Solution:
36.1/102.4 = (361/10) / (1024/10) = 361/1024.Now √(361/1024) = √361 / √1024.√361 = 19, √1024 = 32.Therefore, value = 19/32.Verification / Alternative check:Compute (19/32)^2 = 361/1024 = 36.1/102.4, confirming exactness.
Why Other Options Are Wrong:
- 29/32 and 29/62 have incorrect numerators/denominators.
- 19/72 does not square to 361/1024.
- “None of these” is not needed since 19/32 appears.
Common Pitfalls:Mis-scaling decimals or taking the square root of 1024 wrongly. Remember 1024 = 2^10, so √1024 = 32.
Final Answer:19/32