Waves Part 2

Two strings (A,B) having linear densities µA=2×10−4kg∕m and, µB=4×10−4kg∕m and lengths LA=2.5m and LB=1.5m 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 t1 and t2, respectively, to reach the joint. The ratio t1∕t2 is: