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A train speeds past a pole in 15 seconds and a platform 100 m long in 25 seconds. Its length is:

A train speeds past a pole in 15 seconds and a platform 100 m long in 25 seconds. Its length is:
A.50 mB.150 m
C.200 mD.Data inadequate

Answer: Option B
Explanation:
Let the length of the train be x metres and its speed by y m/sec.
Then,x= 15     =>     y =x.
y15
Thereforex + 100=x
2515
=> 15(x + 100) = 25x
=> 15x + 1500 = 25x
=> 1500 = 10x
=> x = 150 m.

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