Answer:
Kim used 6 decals on each car
Step-by-step explanation:
1. Let's review all the information given to answer the question:
Number of card Kim decorated = 6
Number of mopeds Kim decorated = 3
Decals used on the cars = 3/4
Decals used on the mopeds = 1/4 of the remaining
Decals remaining = 9
2. Let's calculate how many decals Kim used on cars:
x = Number of decals before starting to decorate
x - 3x/4 -1/4 (x - 3x/4) = 9
x - 3x/4 -x/4 + 3x/16 = 9
16x - 12x -4x + 3x = 144 (16 as Lowest common denominator)
3x = 144
x = 48 (Dividing b y 3)
Kim had 48 decals before starting to decorate
3/4x = 36
3/4 * 48 = 36
Kim used 36 decals to decorate the cars
36/6 = 6
Kim used 6 decals on each car