A train 210 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?  Choose the correct option:
A) 40 sec
B) 50 sec
C) 44 sec
D) 49 sec
E) 28 sec
Speed = 45 * 5/18 = 25/2 m/sec   Total distance covered = 210 + 140= 
<gadget id="calculator">210 + 140</gadget>
<output>350</output>
350 m   Required time= 350 * 2/25= 
<gadget id="calculator">350 * 2/25</gadget>
<output>28</output>
28 sec   Answer:28 sec
<result>E</result>
A train 210 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?