Square root of a small decimal: Compute √0.00059049 and select the exact decimal value.
Aptitude
Square Root and Cube Root
Difficulty: Easy
Choose an option
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A.243
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B.0243
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C.00243
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D.000243
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E0.2430
Answer
Correct Answer: .0243
Explanation
Introduction / Context:Recognizing digit patterns helps here: 59049 is a familiar square (243^2). We only need to account for decimal places correctly when taking the square root.
Given Data / Assumptions:
- Number: 0.00059049.
- We know 243^2 = 59049.
Concept / Approach:If a^2 = 59049, then (a/10^k)^2 = 0.00059049 for the appropriate k. Count decimal places to determine the square-root shift.
Step-by-Step Solution:
59049 has 5 digits; here 0.00059049 = 59049 / 10^8.√(59049 / 10^8) = 243 / 10^4 = 0.0243.Therefore, √0.00059049 = 0.0243.Verification / Alternative check:(0.0243)^2 = 0.00059049 (since 243^2 = 59049 and (10^4)^2 = 10^8).
Why Other Options Are Wrong:
- .243 squares to 0.059049 (ten times too large).
- .00243 squares to 0.0000059049 (ten times too small).
- .000243 is off by two decimal places for the square root.
Common Pitfalls:Miscalculating decimal-place shifts when taking square roots. Count digits carefully.
Final Answer:.0243