A vehicle with mileage 15 km per litre contains 2 L of fuel . The vehicle gets some defect as a result of which 5 L of fuel gets wasted per hour when the engine is on. With what minimum speed the vehicle has to move to travel 20 km with the existing amount of fuel, if it travels with a uniform speed?

To find the minimum speed, we must calculate the total fuel consumption over time. Let the speed be 'v' km/h. The time taken to travel 20 km is 20/v hours. During this time, the fuel wasted due to the defect is 5 * (20/v) = 100/v litres. Additionally, the vehicle consumes fuel for driving; at a mileage of 15 km/L, it uses 20/15 = 4/3 litres for the 20 km distance. The total fuel used (100/v + 4/3) must not exceed the available 2 L. Solving the inequality 100/v + 4/3 ≤ 2 leads to 100/v ≤ 2/3, which simplifies to v ≥ 150 km/h. While the provided snippets discuss general fuel efficiency and the impact of speed on consumption, the specific calculation relies on the mathematical relationship between distance, speed, and time. Thus, the minimum speed required is 150 km/h.