Two trains 105 meters and 90 meters long, run at the speeds of 45 kmph and 72 kmph respectively, in opposite directions on parallel tracks. The time which they take to cross each other, is:
A. 8 seconds
B. 6 seconds
C. 7 seconds
D. 5 seconds
Answer: Option B
Solution(By Examveda Team)
Length of the 1st train = 105 m Length of the 2nd train = 90 m Relative speed of the trains,= 45 + 72 = 117 kmph= $$\frac{{117 \times 5}}{{18}}$$ = 32.5 m/sec Time taken to cross each other,= $$\frac{{{\text{Length}}\,{\text{of}}\,{1^{{\text{st}}}}\,{\text{train}} + {\text{length of}}\,{2^{{\text{nd}}}}\,{\text{train}}}}{{{\text{relative }}\,{\text{speed }}\,{\text{of}}\,{\text{the }}\,{\text{trains}}}}$$ ∴ Time taken = $$\frac{{195}}{{32.5}}$$ = 6 secs.Join The Discussion
Comments ( 1 )
Related Questions on Speed Time and Distance
A. 48 min.
B. 60 min.
C. 42 min.
D. 62 min.
E. 66 min.
A. 262.4 km
B. 260 km
C. 283.33 km
D. 275 km
E. None of these
A. 4 hours
B. 4 hours 30 min.
C. 4 hours 45 min.
D. 5 hours
117*5/18..
Can't understand...
Can you explain??