A train crosses a platform of 350 m in 15 sec, same train crosses another platform of length 500m in 20 sec. then find the length of the train? Pick one:
A) 100 m
B) 180 m
C) 159 m
D) 250 m
E) 152 m

Rationale: "length of the train be ‘ x ’ x + 350 / 15 = x + 500 / 20 4 x + 1400 = 3 x + 1500 x = 100 m answer : a"
Answer: A