**Q) **Find the HCF of 506 and 1155.

**Ans: **

By prime factorisation, we get:

506 = 2 x 11 x 23

1155 = 3 x 5 x 7 x 11

Since HCF is all the factors between the two numbers and here 11 is the only factor between the two numbers

** ∴ HCF = 11**

**Q) **Find the HCF of 506 and 1155.

**Ans: **

By prime factorisation, we get:

506 = 2 x 11 x 23

1155 = 3 x 5 x 7 x 11

Since HCF is all the factors between the two numbers and here 11 is the only factor between the two numbers

** ∴ HCF = 11**