A 180 m long train crosses another 270 m long train running in the opposite direction in 12 seconds. If the shorter train crosses a pole in 12 seconds, what is the speed of longer train?
Speed of the shorter train = 180/12 = 15 m/sec Let the speed of the longer train be x km/hr According to the question, ⇒ (15 + x) = (180 + 270)/12 ⇒ 15 + x = 450/12 ⇒ x = 450/12 – 15 = 270/12 ⇒ x = 90/4 x 18/5 = 81 km/hr