P = QQQ = Q × 111 ⇒ $111 = 3 \times 37$

So, P = Q × 3 × 37

Also, $481 = 13 \times 37$

Therefore, both P and 481 share the common factor 37. Since Q (1–9) cannot be 13, no further common factor exists.

Hence, HCF(P, 481) = 37.