In each of the following questions, a question is followed by two statements. Read both the statements and find which statements are required to answer the question and answer accordingly. What is the speed of a train? Statement I: The train crosses a signal pole in 12 seconds and a platform of length 300 meters in 27 seconds. Statement II: The train crosses another train of equal length running in the opposite direction at a speed of 60 km/h in 18 seconds.

From Statement I, let the length of the train be L meters and its speed be S m/s. ATQ, L = S * 12 And, L + 300 = S * 27 Or, 12S + 300 = 27S Or, 15S = 300 So, S = 20 m/s So, the speed of the train is 20 m/s (or 72 km/h). Thus, Statement I alone is sufficient to answer the question. From Statement II, let the length of the train be L meters and its speed be S m/s. ATQ, Speed of the other train = 60 km/h = 60 * (5/18) = 50/3 m/s Since they run in opposite directions, relative speed = S + 50/3 Or, 2L = (S + 50/3) * 18 Since we have two variables L and S and only one equation, we cannot find the speed of the train. Thus, Statement II alone is not sufficient to answer the question. Hence, the correct answer is A.