The HCF of co-prime numbers 4 and 15 was found as follows by factorization:

[tex]\[4 = 2 \times 2\][/tex]
[tex]\[15 = 3 \times 5\][/tex]

Since there is no common prime factor, the HCF of 4 and 15 is 0.

Is the answer correct? If not, what is the correct HCF?



Answer :

The answer is not correct. Let's find the correct Highest Common Factor (HCF) of the numbers 4 and 15 using the prime factorization method in a step-by-step fashion.

### Step-by-Step Solution

1. Prime Factorization:
- For [tex]\( 4 \)[/tex]:
The prime factors of 4 are [tex]\( 2 \times 2 \)[/tex]. So, we can write:
[tex]\[ 4 = 2^2 \][/tex]

- For [tex]\( 15 \)[/tex]:
The prime factors of 15 are [tex]\( 3 \times 5 \)[/tex]. So, we can write:
[tex]\[ 15 = 3 \times 5 \][/tex]

2. Identify Common Factors:
Now, we compare the prime factors of 4 and 15 to identify any common factors:
- Factors of 4: [tex]\( 2 \)[/tex]
- Factors of 15: [tex]\( 3, 5 \)[/tex]

As we can see, there are no common prime factors between 4 and 15.

3. Conclusion:
When there are no common prime factors between two numbers, those numbers are termed co-prime (or relatively prime). The Highest Common Factor (HCF) of co-prime numbers is always 1 because 1 is the only number that can divide both of them without leaving a remainder.

### Final Answer:
Therefore, the HCF of 4 and 15 is:
[tex]\[ \boxed{1} \][/tex]