With an uniform speed, a car covers a distance in 8 hours. had the speed been increased by 4 km/hr, the same distance could have been covered in 7 hr and 30 min. What is the distance covered ?
A. 420 km
B. 480 km
C. 520 km
D. 640 km
Answer: Option B
Solution (By Examveda Team)
Let the speed of car be x km/hrDistance = Speed × Time
Distance = 8x km
According to the question,
$$\eqalign{ & \Rightarrow \left( {x + 4} \right) \times 7.5 = 8x \cr & \Rightarrow 7.5x + 30 = 8x \cr & \Rightarrow 8x - 7.5x = 30 \cr & \Rightarrow 0.5x = 30 \cr & \Rightarrow x = \frac{{30}}{{0.5}} = 60{\text{ km/hr}} \cr} $$
Required distance :
= 8 × 60
= 480 km

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