A 600 meter long train crosses a signal post in 40 seconds. How long will it take to cross a 3 kilometer long bridge, at the same speed?	Choose the correct option.
A) 8 min B) 24 min C) 12 min D) 6 min E) 4 min
4 minxplanation:   S = 600/40= 
<gadget id="calculator">600/40</gadget>
<output>15</output>
15 mps   S= 3600/15= 
<gadget id="calculator">3600/15</gadget>
<output>240</output>
240 sec= 4 min   4 min)
<result>E</result>
A 600 meter long train crosses a signal post in 40 seconds. How long will it take to cross a 3 kilometer long bridge, at the same speed?