Answer:

Step-by-step explanation:
The figure is a cube
The surface area of a cube is equal to

where
b is the length side of the cube
In this problem we have
substitute

8 baseball cards + 5 football cards= 13 cards
8 baseball cards per every 13 total cards.
78÷13=6
6×8= 48
48 Baseball Cards in total
About 38 cars. 300/8= 37.5 cars. There is no such thing as 0.5 of a car so round up to the nearest whole number.