Answers

2015-06-25T17:36:32+05:30
Let the  length of the train be x  m.
Given,
 \frac{450+x}{27} = \frac{330+x}{21 } (speed is equal in both cases).
= \frac{450+x}{9} = \frac{330+x}{7}  
7(450+x)=9(330+x)
3150+7x=2970+9x
2x=3150-2970  
 x=180/2=90

Length of the train:90 m.
Given , 450 m + 90  m=540 m is covered in 27 seconds.
Therefore, speed=540/27 m/s
=20 m/s
Ans:The required speed is 20 m/s...
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