A passenger sitting in a train A moving at 90 km / h observes another train B moving in the opposite direction for 8 s. If the velocity of the train…

A passenger sitting in a train $\displaystyle A$ moving at $\displaystyle 90 \mathrm{~km} / \mathrm{h}$ observes another train $\displaystyle B$ moving in the opposite direction for $\displaystyle 8$ s . If the velocity of the train B is $\displaystyle 54$ km/h, then length of train $\displaystyle B$ is: