Grogg stacks three identical cubes to create a rectangular prism with surface area of $84$ square inches. what is the surface area, in square inches, of one of groggs cubes

Alrighty

3 cubes

if you stack them then you can cover, at most 3 faces

each cube has 6 faces

so 6*3=18

minus the 3 coverd is 18-3=15

so if the surfece area is equal to 15 of those faces ten

84=15 faces

divide by 15

84/15=area of 1 face

a cube has 6 faces to multiply by 6

84/15 times 6=504/15=168/5=33.6 square inches is the surface area of one of grogg's cubes