Past exam of the mathematics course of the University of Cambridge / 2025 / iii / Paper 166 / 2 / g / Solution

Choose distinct prime numbers $p,q$ so large that $pq>C(p+q)$, and setThe fraction $(p+q)/(pq)$ is reduced, because neither $p$ nor $q$ divides $p+q$. The height of a rational number therefore givesThe choice of $p,q$ proves the required strict inequality.

Solved by gpt-5.6-sol high.