Speed of Waves question from JEE Main 2026 (21 Jan, Shift 1)

Two strings $(A, B)$ having linear densities $\mu_A = 2 \times 10^{-4}\text{ kg/m}$ and, $\mu_B = 4 \times 10^{-4}\text{ kg/m}$ and lengths $L_A = 2.5\text{ m}$ and $L_B = 1.5\text{ m}$ respectively are joined. Free ends of $A$ and $B$ are tied to two rigid supports $C$ and $D$, respectively creating a tension of 500 N in the wire. Two identical pulses, sent from $C$ and $D$ ends, take time $t_1$ and $t_2$, respectively, to reach the joint. The ratio $t_1/t_2$ is: