a truck left station A at a speed of 40kph and reached 400km

a truck left station A at a speed of 40kph and reached 400km. 4hrs later a car left the same station and tried to chase the truck. What should be the speed of the car in order to overtake the truck ?

Solution

The car will overtake the truck at any speed greater than 40 kph. The faster the car goes, the less time it will take.