A 500 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 most appropriate option:
A) 2 min 48 sec
B) 4 min 48 sec
C) 4 min 38 sec
D) 4 min 18 sec
E) 4 min 8 sec
S = 500/40= 
<gadget id="calculator">500/40</gadget>
<output>25/2 = around 12.5</output>
12.5 mps   S= 3600/12.5= 
<gadget id="calculator">3600/12.5</gadget>
<output>288</output>
288 sec= 4 min 48 sec   ANSWER:4 min 48 sec
<result>B</result>
A 500 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?