Shyam drives his car 30 km at a speed of 45 km/h and, for the next 1 h 20 m, he drives it at a speed of 51 km/h. Find his average speed (in km/h) for the entire journey.
A. 49
B. 48
C. 48.5
D. 47
Answer: Option A
Solution(By Examveda Team)
$$\eqalign{ & {\text{Time}} = 1\,{\text{hr}}\,20\,{\text{m}} = \frac{4}{3}{\text{hr}} \cr & {\text{Speed}} = 51{\text{ km/hr}} \cr & \therefore {\text{Distance}} = \frac{4}{3} \times 51 = 68 \cr & {\text{Average speed}} = \frac{{{\text{Total distance}}}}{{{\text{Total time}}}} \cr & = \frac{{30 + 68}}{{\frac{{30}}{{45}} + \frac{4}{3}}} \cr & = \frac{{98}}{{\frac{2}{3} + \frac{4}{3}}} \cr & = 49{\text{ km/hr}} \cr} $$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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