A train travels a distance of 480 km at a uniform speed. If the speed had been 8 km/hr less, then it would have taken 3 hours more to cover the same distance. If the initial speed of the train is x km/hr, then representation of this information algebraically is :

1. x² − 8x − 1280 = 0

2. x² + 8x + 1280 = 0

3. x² − 8x + 1280 = 0

4. x² + 8x − 1280 = 0

Two cars X and Y use 1 litre of diesel to travel x km and (x + 3) km respectively. If both the cars covered a distance of 72 km, then :

The amount of diesel used by car X is:

1. 6 litres

2. 12 litres

3. 18 litres

4. 24 litres