Answer: Option B
Length of the train = (15 x 20)m = 300 m.
Let the length of the platform be x metres.
x + 300 = 540
x = 240 m.
Let the speeds of the two trains be x m/sec and y m/sec respectively.
Then, length of the first train = 27x metres,
and length of the second train = 17y metres.
27x + 17y = 23x + 23y
4x = 6y
Answer: Option C
Time = 30 sec.
Let the length of bridge be x metres.
2(130 + x) = 750
x = 245 m.
= 45 km/hr.
Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.
x - 5 = 45 x = 50 km/hr.