Ram travels a certain distance at 3 km/hr and reaches 15 min late. If he travels at 4 km/hr he reaches 15 min earlier. The distance he has to travel is ?
4.5 km.
6 km.
7.2 km.
12 km.
Correct Option: B
Let the distance be x km. Then, x/3 - x/4 = 30/60 ⇒ (4x - 3x ) / 12 = 1/2 ∴ x = 6 km.
