Question

A car travels a certain distance in four hours. If it had travelled 10 km faster, it would have taken only three hours. Find the distance

Answer 1

Let the speed of car in first case be xkm/hr and distance travelled be d.
So d= x× 4=4x........1
In the second case the speed is increased by 10km/hr.
So d=(10+x)3
So d= 30+3x.......2
So from eq 1 and eq 2
4x=30+3x
So x= 30km/hr
Therefore distance travelled = 30×3= 90 km