A train ,120 meters long travels at a speed of 45 km/hr crosses a bridge in 30 seconds. The length of the bridge is Pick one:	A) 270 m	B) 255 m	C) 235 m	D) 220 m	E) 240 m
Explanation:   Assume the length of the bridge = x meter   Total distance covered = 120+x meter   total time taken = 30s   speed = Total distance covered /total time taken = (120+x)/30 m/s   =&gt; 45 Ã— (10/36) = (120+x)/30   =&gt; 45 Ã— 10 Ã— 30 /36 = 120+x   =&gt; 45 Ã— 10 Ã— 10 / 12 = 120+x   =&gt; 15 Ã— 10 Ã— 10 / 4 = 120+x   =&gt; 15 Ã— 25 = 120+x = 375   =&gt; x = 375-120= 
<gadget id="calculator">375-120</gadget>
<output>255</output>
255   Answer: Option 255 m
<result>B</result>
A train ,120 meters long travels at a speed of 45 km/hr crosses a bridge in 30 seconds. The length of the bridge is