If n faces of a cube are painted, the area of the unpainted faces is what fraction of the total surface area of the cube?

A) n/6
B)n/8
C)n-6/6
D)6-n/6
E)6-n/8

Question

If n faces of a cube are painted, the area of the  unpainted faces is what fraction of the total surface area of the cube?

A) n/6
B)n/8
C)n-6/6
D)6-n/6
E)6-n/8

anonymous · Answer

D

anonymous · Answer

because

anonymous · Answer

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if you look at this shape which can fold into a cube, we see that there are 6 face

anonymous · Answer

therefore when we paint one face, we are painting 1/6 percent of the total surface..

anonymous · Answer

if we paint 2, we cover 2/6 or 1/3 percent of the total surface.... 
paint 3, we cover 3/6 or 1/2
paint 4, we cover 4/6 or 2/3
paint 5, we cover 5/6
paint 6 we cover 6/6 or 100% 
hence the pattern we find is 6-(n/6)