How long does a train 110 m long running at the speed of 72 km/hr takes to cross a bridge 138 m length? Choose the correct answer:
A) 82.1 sec. B) 12.4 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 + 138= 
<gadget id="calculator">110 + 138</gadget>
<output>248</output>
248 m.   Required time= 248/20= 
<gadget id="calculator">248/20</gadget>
<output>62/5 = around 12.4</output>
12.4 sec.   Answer: 12.4 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 138 m length?