A train moves past a post and a platform 264 m long in 8 seconds and 20 seconds respectively. What is the speed of the train?  Choose the correct choice from the following answers:  A) 79.2 km/hr  B) 69 km/hr  C) 74 km/hr  D) 61 km/hr  E) none of these
Let x is the length of the train and v is the speed   Time taken to move the post = 8 s   =&gt; x/v = 8   =&gt; x = 8v --- (1)   Time taken to cross the platform 264 m long = 20 s   (x + 264)/v = 20   =&gt; x + 264 = 20v ---(2)   Substituting equation 1 in equation 2, we get   8v +264 = 20v   =&gt; v = 264/12= 
<gadget id="calculator">264/12</gadget>
<output>22</output>
22 m/s= 22 × 36/10 km/hr = 79.2 km/hr   ANSWER:69 km/hr
<result>B</result>
A train moves past a post and a platform 264 m long in 8 seconds and 20 seconds respectively. What is the speed of the train?