The following questions are accompanied by three statements (I), (II), and (III). You have to determine which statements(s) is/are sufficient/necessary to answer the questions.

Two trains A and B are travelling towards each other on the same track. The initial distance between them is 91 km. Find the time, when the two trains will collide.

I: The speed of train A is 65 km/h and the speed of B is 104 km/h more than that of train A.

II: The ratio of speeds of the two trains is 5: 13.

III. Faster train can travel 312 km in 3 hr.