A journey of 192 km between two cities take 2 hours less by a fast train than by a slow train. If the average speed of the slow train is 16 km/hr less than that of the fast train, the average speed of the fast train is :
A. 32 km/hr
B. 36 km/hr
C. 48 km/hr
D. 64 km/hr
Answer: Option C
Solution(By Examveda Team)
Let the speed of the fast train be x km/hrThen, speed of the slow train = (x - 16) km/hr
$$\eqalign{ & \therefore \frac{{192}}{{x - 16}} - \frac{{192}}{x} = 2 \cr & \Rightarrow \frac{1}{{x - 16}} - \frac{1}{x} = \frac{1}{{96}} \cr & \Rightarrow {x^2} - 16x - 1536 = 0 \cr & \Rightarrow \left( {x - 48} \right)\left( {x + 32} \right) = 0 \cr & \Rightarrow x = 48\,\text{km/hr} \cr} $$
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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