To find out how many cans of white paint Emma will need to mix with 12 cans of pink paint, we can use the proportion of white paint to pink paint that she is currently using: 6 cans of white paint to every 4 cans of pink paint.
We can set up an equation using the proportion:
white paint/pink paint = 6/4 =3/2
We know that Emma wants to use 12 cans of pink paint, so we can use this information to solve for the number of cans of white paint she needs:
white paint/pink paint = 3/2
white paint = (3/2) * pink paint
white paint = (3/2) * 12 cans
white paint = 18 cans
So Emma will need 18 cans of white paint to mix with 12 cans of pink paint to get the desired color.