Answer: 8 cups of white paint is used.
Step-by-step explanation:
In a lilac paint mixture 40% of the mixture is white paint 20% is blue and the rest is red. This means that the percentage of red paint in the mixture is 100 - (40 + 20) = 40%
There are four cups of blue paint used in a batch of lilac paint. This means that 20% of the total number of cups of paint used in a batch of lilac paint is 4.
Assuming that the total number of cups of paint in the mixture is x, then,
20/100 × x = 4
0.2x = 4
x = 4/0.2 = 20
Therefore, the number of cups of white paint used is
40/100 × 20 = 0.4 × 20
= 8 cups
