A train passes an active signal light in 10 seconds. If the length of the train is 150 meters, find its speed in km/h. MCQ with Answer and Explanation

Explanation:
Speed of train = 240 / 12 = 20 m/s. Total distance to pass platform = 240 + 360 = 600 meters. Time taken = 600 / 20 = 30 seconds.

Explanation:
New speed = 5/6 of usual speed => New time = 6/5 of usual time. Difference = 1/5 of usual time = 10 minutes. Typical baseline time = 10 * 5 = 50 minutes.

Explanation:
Let original speed be s. 360 / (s - 10) - 360 / s = 2 => 180 / (s - 10) - 180 / s = 1 => 180(10) = s(s - 10) => 1800 = s(s - 10). Solving s^2 - 10s - 1800 = 0 gives (s - 45)(s + 40) = 0. Since speed is positive, s = 45 km/h.