Train A travels east at a constant speed of \(25\text{ m/s}\) relative to the ground, while Train B travels west at a constant speed of \(15\text{ m/s}\) relative to the ground on an adjacent parallel track. A passenger on Train A walks toward the rear of the train at a speed of \(3\text{ m/s}\) relative to Train A. What is the speed of the passenger relative to an observer seated on Train B?