A police car B is chasing a culprit’s car A. Car A and B are moving at constant speed `V_(1) = 108 km//hr` and `V_(2) = 90 km//hr` respectively along a straight line. The police decides to open fire and a policeman starts firing with his machine gun directly aiming at car A. The bullets have a velocity `u = 305 m//s` relative to the gun. The policeman keeps firing for an interval of `T_(0) = 20 s`. The Culprit experiences that the time gap between the first and the last bullet hitting his car is `Deltat`. Find `Deltat`.