A 900 m long train crosses a platform in 39 sec while it crosses a signal pole in 18 sec. What is the length of the platform?  Choose the correct choice from the following answers.
A) 1000
B) 1050
C) 1060
D) 370
E) 380
Speed = 900/18= 
<gadget id="calculator">900/18</gadget>
<output>50</output>
50/1 m/sec.   Let the length of the platform be x meters.   Then, (x + 300)/39= 50/1   =&gt; x = 1950 m.   L=1950-900= 
<gadget id="calculator">1950-900</gadget>
<output>1_050</output>
1050   Answer: Option 1050
<result>B</result>
A 900 m long train crosses a platform in 39 sec while it crosses a signal pole in 18 sec. What is the length of the platform?