1.  With a uniform speed a car covers the distance in 8 hours. Had the speed been increased by 4 km/hr, the same distance could have been covered in 7 hours 30 minutes. What is the distance covered ?
A. 420 km
B. 480 km
C. Cannot be determined
D. None of these

Answer: Option B

Explanation:

Let the distance be X km.

Then , X/7 - X/8 =4

<=> 2X/15 - X/8 = 4

<=> X = 480 km