Let x = Barbie's number
1/3 x -20 = 72
1/3 x = 92
x = 92*3=276
A box of donuts would cost: b = 3.84 + 0.18f
First, we have to find the total cost of the donuts.
12 x 0.32 = 3.84
Next, we need to determine the cost of the box. However, we don't know the surface area, just the cost per foot. We can multiply the number of square feet of the box by $0.18 to find the cost.
So our equation could be: b = 3.84 + 0.18f (where f is the surface area of the box in square feet)
