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Two trains of equal lengths take 10 seconds and 15 seconds r


Two trains of equal lengths take 10 seconds and 15 seconds respectively to cross a telegraph post. If the length of each train be 120 metres, in what time (in seconds) will they cross each other travelling in opposite direction?

A.10B.12
C.15D.20



Answer: Option B
Explanation:
Speed of the first train =(120(m/sec = 12 m/sec.
10
Speed of the second train =(120(m/sec = 8 m/sec.
15
Relative speed = (12 + 8) = 20 m/sec.
Therefore Required time =[(120 + 120)]sec = 12 sec.
20

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