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 $500 \text{ N}$ 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: