Answer: 4.5 litres
Explanation:
If 1.5 liters of red paint is mixed with white paint to make 6 liters of pink paint, then the ratio of red paint to the total mixture is 1.5/6 = 0.25.
Since the pink paint is made by mixing red paint with white paint, the ratio of white paint to the total mixture is 1 - 0.25 = 0.75.
Therefore, to find the amount of white paint needed, we can set up the following proportion:
1.5/0.25 = x/0.75
Solving for x, we get:
x = 0.75 * 1.5 / 0.25 = 4.5
So, 4.5 liters of white paint is needed to make 6 liters of pink paint.