Alok was travelling in a fog . He passed Ajay who was walking at the rate of 2 Km/ hr in the same direction . Ajay could see the Alok for 6 minute or upto a distance of 0.6 Km. What was the speed of Alok?

Relative speed = (distance covered)÷(time). Alok covers 0.6 km in 6 minutes = 0.1 km/min. Ajay walks at 2 km/hr = 2÷60 km/min = 1/30 km/min. Since they move in same direction, relative speed = Alok's speed - Ajay's speed. Alok's speed = 0.1 + 1/30 = 4/30 km/min = 8 km/hr. Answer C is correct. The key is understanding relative speed concept.