A train moves fast a telegraph post and a bridge 245 m long in 8 sec and 20 sec respectively. What is the speed of the train?
Choices:
A) 73.5
B) 39.5
C) 79.9
D) 79.2
E) 79.1
Let the length of the train be x m and its speed be y m/sec.   Then, x/y = 8 =&gt; x = 8y   (x + 245)/20 = y   y = 20.42   Speed = 20.42 m/sec = 20.42 * 18/5 = 73.5 km/hr.   73.5nswer:73.5
<result>A</result>
A train moves fast a telegraph post and a bridge 245 m long in 8 sec and 20 sec respectively. What is the speed of the train?