Step 1: Let the numbers be \( 15x \) and \( 11x \), where \( x \) is the common multiplier.
Step 2: Since the HCF of the numbers is 12, we have:
\[
\text{HCF}(15x, 11x) = 12
\]
Step 3: The HCF of 15 and 11 is 1, so:
\[
x = 12
\]
Step 4: The numbers are:
\[
15x = 15 \times 12 = 180
\]
\[
11x = 11 \times 12 = 132
\]
Thus, the numbers are 180 and 132.