Question: Which of the following pairs of numbers has an HCF of 1? (2023)
Options:
8 and 12
15 and 28
9 and 27
14 and 21
Correct Answer: 15 and 28
Exam Year: 2023
Solution:
The HCF of 15 and 28 is 1, making them coprime.
Which of the following pairs of numbers has an HCF of 1? (2023)
Practice Questions
Q1
Which of the following pairs of numbers has an HCF of 1? (2023)
8 and 12
15 and 28
9 and 27
14 and 21
Questions & Step-by-Step Solutions
Which of the following pairs of numbers has an HCF of 1? (2023)
Step 1: Understand what HCF means. HCF stands for Highest Common Factor, which is the largest number that divides two or more numbers without leaving a remainder.
Step 2: Identify the two numbers you want to check. In this case, the numbers are 15 and 28.
Step 3: List the factors of each number. The factors of 15 are 1, 3, 5, and 15. The factors of 28 are 1, 2, 4, 7, 14, and 28.
Step 4: Find the common factors between the two lists. The only common factor of 15 and 28 is 1.
Step 5: Determine the HCF. Since the highest common factor is 1, it means that 15 and 28 have no other common factors.
Step 6: Conclude that since the HCF is 1, the numbers 15 and 28 are coprime, meaning they do not share any factors other than 1.
No concepts available.
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