Two trains of length 100 meters and 200 meters are 630 meters apart. They are moving towards each other on parallel tracks, at speeds of 90 km/h and 72 km/h. After how many seconds will the trains meet?
Choose the correct choice from the following options
A) 12 B) 14 C) 16 D) 18 E) 20

Rationale: the speeds are 90000 / 3600 = 25 m / s and 72000 / 3600 = 20 m / s the relative speed is 45 m / s . time = 630 / 45 = 14 seconds the answer is b .
Answer: B