The ratio between the speeds of two trains is 7 : 8. If the second train runs 400 km in 4 hours, then the speed of the first train is:
A. 70 km/hr
B. 75 km/hr
C. 84 km/hr
D. 87.5 km/hr
Answer: Option D
Solution(By Examveda Team)
$$\eqalign{ & {\text{Let}}\,{\text{the}}\,{\text{speed}}\,{\text{of}}\,{\text{two}}\,{\text{trains}}\,{\text{be}}\,7x\,{\text{and}}\,8x\,{\text{km/hr}} \cr & {\text{Then}},\,8x = {\frac{{400}}{4}} = 100 \cr & \Rightarrow x = {\frac{{100}}{8}} = 12.5 \cr & \therefore {\text{Speed}}\,{\text{of}}\,{\text{first}}\,{\text{train}} \cr & = \left( {7 \times 12.5} \right){\text{km/hr}} \cr & = 87.5\,{\text{km/hr}} \cr} $$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
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