Two trains of equal lengths take 15 seconds and 30
seconds respectively to cross a telegraph post. If the length of each train be 240 metres, in what time will they cross each other travelling in opposite direction?
A24 secCorrect AnswerIncorrect Answer
B20 secCorrect AnswerIncorrect Answer
C36 secCorrect AnswerIncorrect Answer
D16 secCorrect AnswerIncorrect Answer
Solution
Speed of the first train = [240/15] m/sec = 16 m/sec Speed of the second train = [240/30] m/sec = 8 m/sec Speed = (16 + 8) m/sec = 24 m/sec Required time = (240 + 240)/24 sec = 20 sec