Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 280 * 2/35 = 16 sec
This justifies what answer for what question? Q & A:
A train 280 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 11
(B) 16
(C) 188
(D) 199
(E) 12
(B)