how long does a train 250 meters long running at the rate of 72 km / hr take to cross a bridge 150 meters in length?	Select the correct option:
A) 10 sec B) 20 sec C) 25 sec D) 30 sec E) 35 sec
<gadget id="calculator">250 + 150</gadget>
<output>400</output>

<gadget id="calculator">10 / 36</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">72 * (5/18)</gadget>
<output>20</output>

<gadget id="calculator">400 / 20</gadget>
<output>20</output>

<result>B</result>
how long does a train 250 meters long running at the rate of 72 km / hr take to cross a bridge 150 meters in length?
divide(add(250, 150), multiply(72, const_0_2778))
"distance = length of train + length of bridge = 250 + 150 = 400 speed = 72 km / hr = 72 * 5 / 18 = 20 m / s required time = 400 / 20 = 20 seconds answer is b"