What is the Highest Common Factor (HCF) of 21.97, 15.21, 16.9, 18.59 and 20.28?
2021
What is the Highest Common Factor (HCF) of 21.97, 15.21, 16.9, 18.59 and 20.28?
Answer: C. 1.69 — Make decimals uniform: The numbers are 21.97, 15.21, 16.90, 18.59, and 20.28. Convert to integers: Multiply each by 100 to remove decimals: 2197, 1521, 1690,…
- A.
3
- B.
1.3
- C.
1.69
- D.
13
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Correct answer: C
Make decimals uniform: The numbers are 21.97, 15.21, 16.90, 18.59, and 20.28.
Convert to integers: Multiply each by 100 to remove decimals: 2197, 1521, 1690, 1859, and 2028.
Prime Factorization:
2197 = 13³
1521 = 3² × 13²
1690 = 2 × 5 × 13²
1859 = 11 × 13²
2028 = 2² × 3 × 13²
Find HCF of integers: The common factor is 13² = 169.
Restore decimal: Divide by 100 = 1.69.
Final Answer: Option 3 (1.69)
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