Two trains are moving towards each other at the speeds of 70 km/h and 85 km/h. Their lengths are 210 m and 255 m, respectively. How much time will they take to cross each other completely?
Answer & explanation
Correct answer: option 3
Relative speed ( when moves in opposite direction ) = 70 + 85 = 165 km/h
165 km/h = 155 × \(\frac{5 }{18 }\) = \(\frac{775 }{18 }\)
Total distance = 210 + 255 = 465 m
Time taken = \(\frac{465 × 18 }{775 }\)
= 10.8 sec