Question

WILL GIVE BRAINLIEST!!!! A 5×5×5 wooden cube was painted and then sawed into 1×1×1 cubes.
b. How many 1×1×1 cubes are completely unpainted?
c. How many 1×1×1 cubes have exactly two faces painted?

Answer 1

Answer:

b.27 c. 36 (THIS ANSWER IS CORRECT....IM IN RSM ;)

Step-by-step explanation:

The bottom one is for b.

Okay now for c. Lets first think about every cube that has two faces painted. all the cubes on the edges right? So that would be 5*12=60 but that isn't the answer because the problem stated EXACTLY two faces. That means every cube on a vertices doesn't count because it has 3 faces painted. If you look back at the edges and don't count the cubes on the vertices you will see that there are 3 cubes that fit these guide lines on each edge and there are 12 edges. So your answer would be 3*12=36!

You can do it simply by seeing that the outer cubes will have their upper surfaces painted and thus 5*5 squares for each outer surface which will leave a cube with 3×3×3 dimensions. It is 3*3*3 because on every side all the outer cubes will be painted. So one layer of the cube will be decreased by one on all sides. So the length width and height will all end up as 5-2=3. Its kind of hard to explain and i suggest you draw it out if you don't understand...

Answer 2

The number of 1×1×1 cubes that are completely unpainted is 27 and the number of 1×1×1 cubes have exactly two faces painted. is 36.

What is an expression?

Expression in maths is defined as the collection of the numbers variables and functions by using signs like addition, subtraction, multiplication, and division.

b. BY looking that the outer cubes will have their upper surfaces painted and thus 5 x 5 squares for each outer surface which will leave a cube with 3×3×3 dimensions.

It is 3 x 3 x 3 because on every side all the outer cubes will be painted. So one layer of the cube will be decreased by one on all sides. The length width and height will all end up as 5-2=3.

c. Let's first think about every cube that has two faces painted. So that would be 5x 12=60 but that isn't the answer because the problem stated exactly two faces.

That means every cube on vertices doesn't count because it has 3 faces painted. If you look back at the edges and don't count the cubes on the vertices you will see that there are 3 cubes that fit these guidelines on each edge and there are 12 edges.

The number is calculated as:-

N = 3x 12=36

Hence, the number of 1×1×1 cubes that are completely unpainted is 27 and the number of 1×1×1 cubes has exactly two faces painted. is 36.

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