A train speeds past a pole in 15 seconds and a platform 100 m long in 25 seconds. Its length is:
A. 50 m
B. 150 m
C. 200 m
D. Data inadequate
Answer: Option B
Solution(By Examveda Team)
$$\eqalign{ & {\text{Let}}\,{\text{the}}\,{\text{length}}\,{\text{of}}\,{\text{the}}\,{\text{train}}\,{\text{be}}\,x\,{\text{metres}} \cr & \,{\text{and}}\,{\text{its}}\,{\text{speed}}\,{\text{by}}\,y\,{\text{m/sec}} \cr & Then,\,\frac{x}{y} = 15\,\,\,\,\,\, \Rightarrow \,\,\,\,\,y = \frac{x}{{15}} \cr & \therefore \frac{{x + 100}}{{25}} = \frac{x}{{15}} \cr & \Rightarrow 15\left( {x + 100} \right) = 25x \cr & \Rightarrow 15x + 1500 = 25x \cr & \Rightarrow 1500 = 10x \cr & \Rightarrow x = 150m \cr} $$Related Questions on Problems on Trains
A. 120 metres
B. 180 metres
C. 324 metres
D. 150 metres
A. 45 km/hr
B. 50 km/hr
C. 54 km/hr
D. 55 km/hr
A. 200 m
B. 225 m
C. 245 m
D. 250 m
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