How long does a train 110 m long running at the speed of 72 km/hr takes to cross a bridge 140 m length? Pick one:
A) 82.1 sec.  B) 12.5 sec  C) 19.1 sec.  D) 17.1 sec.  E) 42.1 sec.
Speed = 72 * 5/18= 
<gadget id="calculator">72 * 5/18</gadget>
<output>20</output>
20 m/sec   Total distance covered= 110 + 140= 
<gadget id="calculator">110 + 140</gadget>
<output>250</output>
250 m.   Required time= 250/20= 
<gadget id="calculator">250/20</gadget>
<output>25/2 = around 12.5</output>
12.5 sec.   Answer: 12.5 sec
<result>B</result>
How long does a train 110 m long running at the speed of 72 km/hr takes to cross a bridge 140 m length?