Answer:3
Explanation:
The HCF of 3 and 9 is 3. To calculate the HCF (Highest Common Factor) of 3 and 9, we need to factor each number (factors of 3 = 1, 3; factors of 9 = 1, 3, 9) and choose the highest factor that exactly divides both 3 and 9 . i.e 3.