SEAMO 2026 — Paper B — SET 3 — Organizer self-practice Question 3

The value of $\frac{1}{1\times3}+\frac{1}{3\times5}+\frac{1}{5\times7}+\frac{1}{7\times9}$ is $\frac{m}{n}$ in lowest terms. Find the value of $m+n$.