The machine that paints white lines on roads uses 180 litres of paint to paint 6 kilometres of road
Assuming the machine paints two lines (one on each side of the road), this means it is painting 12 kilometres of lines in total.
Therefore, the machine uses 180 litres of paint to paint 12 kilometres of road.
To calculate how much paint is used to paint 1 kilometre of road, we can divide the total amount of paint used (180 litres) by the total length of road painted (12 kilometres):
180 litres / 12 kilometres = 15 litres of paint per kilometre
Therefore, the machine uses 15 litres of paint to paint 1 kilometre of road with white lines.