AP EAMCET Engineering 20 Apr 2019 Shift 2 Paper

A siren placed at a railway platform is emitting a sound of frequency 5 kHz. A passenger sitting in a moving train ‘A’ records the frequency of the siren as 5.5 kHz. During his return journey by train ‘B' he records the frequency of the siren as 6 kHz. The ratio of the speed of train B to that of train A is