A car completed a journey of 400 km in $$12\frac{1}{2}$$ hrs. The first $$\frac{3}{4}$$ of the journey was done at 30 km/hr. Calculate the speed for the rest of the journey.
A. 45 km/hr
B. 40 km/hr
C. 25 km/hr
D. 30 km/hr
Answer: Option B
Solution(By Examveda Team)
$$\eqalign{ & {\text{Total journey = 400}} \cr & \frac{3}{4}{\text{ Journey = 400}} \times \frac{3}{4} \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 300{\text{ km}} \cr} $$Remaining journey = 100 km
Let the speed of car for the rest of journey = x km/hr
According to the question,
$$\eqalign{ & \frac{{300}}{{30}} + \frac{{100}}{x} = 12\frac{1}{2} \cr & 10 + \frac{{100}}{x} = \frac{{25}}{2} \cr & \frac{{100}}{x} = \frac{{25 - 20}}{2} \cr & x = \frac{{100 \times 2}}{5} \cr & x = 40{\text{ km/hr}} \cr} $$
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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