Answer:
Elliot has to wait 11 months before he has enough cars
Step-by-step explanation:
Elliot has 4 display cases with each case being able to hold 15 cars. Thus we know
total # of cars Elliot can place in his display case = 4 * 15 = 60 cars
From this, we can figure out how many more cars Elliot needs by subtracting the amount of cars he already has
# of cars Elliot needs = 60 - 28 = 32 cars
Now to find the number of months Elliot needs, we divide by how many he can buy each month
# of months Elliot needs to save up for = 32 / 3 = 10 2/3
Assuming Elliot does not get his allowance until the end of the month, we will have to round the number of months up to the nearest integer, 11
