Compute the GCD (HCF) of decimal numbers by clearing decimals: GCD of 1.08, 0.36, and 0.90. Demonstrate exact integer reduction.
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A0.03
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B0.9
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C0.18
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D0.108
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E0.06
Answer
Correct Answer: 0.18
Explanation
Introduction / Context:To find the greatest common divisor (GCD) of decimals exactly, convert them to integers by multiplying with a common power of ten, compute the GCD of the integers, and then scale back. This avoids rounding and ensures correctness.
Given Data / Assumptions:
- Decimals: 1.08, 0.36, 0.90
- Use a common factor of 100 to clear two decimal places.
Concept / Approach:Multiply by 100: 1.08 → 108, 0.36 → 36, 0.90 → 90. Compute GCD(108, 36, 90). Then divide the GCD by 100 to return to decimal scale.
Step-by-Step Solution:GCD(108, 36) = 36.GCD(36, 90) = 18.So the scaled GCD is 18. Scale back: 18 ÷ 100 = 0.18.
Verification / Alternative check:Confirm divisibility: 1.08 ÷ 0.18 = 6; 0.36 ÷ 0.18 = 2; 0.90 ÷ 0.18 = 5. All are integers, confirming 0.18 divides each exactly.
Why Other Options Are Wrong:
- 0.108, 0.06, 0.03: Each divides some but not all of the numbers evenly.
- 0.9: Larger than some inputs; not a common divisor of 0.36.
Common Pitfalls:Scaling only some numbers or scaling back incorrectly; using approximate decimal GCDs without exact reduction.
Final Answer:0.18