document.write( "Question 206586: A cube composed of 64 1 x 1 x 1 cubes is painted and then broken apart again into the smaller cubes. How many of the 1 x 1 x 1 cubes will have exactly 2 painted faces?\r
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document.write( "(A) 8 (B) 16 (C) 24 (D) 36 (E) 48 \n" );
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Algebra.Com's Answer #156128 by Theo(13342)![]() ![]() You can put this solution on YOUR website! you have 64 cubes. \n" ); document.write( "----- \n" ); document.write( "cube root of 64 is 4 which means your cubic structure has a length of 4 cubes and a width of 4 cubes and a depth of 4 cubes. \n" ); document.write( "----- \n" ); document.write( "out of these 64 cubes there will be 8 cubes that will have 0 faces painted. \n" ); document.write( "these cubes are in the interior of the cube. \n" ); document.write( "----- \n" ); document.write( "that leaves 64 - 8 = 56 cubes that have at least one face painted. \n" ); document.write( "----- \n" ); document.write( "if you look at each side of the 6 sides of the cube, you will see that there are 4 cubes on each side that will only have 1 face painted. Those are the interior cubes of each side. \n" ); document.write( "since 6 * 4 = 24, you have 24 more cubes that will not have 2 sides painted because they only have 1 side painted. \n" ); document.write( "----- \n" ); document.write( "56 - 24 = 32 cubes are left that will have at least 2 sides painted. \n" ); document.write( "----- \n" ); document.write( "if you look at the corners of your cube you will see that each corner cube will have 3 sides painted. \n" ); document.write( "since there are 8 corners to the cube, that makes 8 cubes that will have more than 2 sides painted. \n" ); document.write( "----- \n" ); document.write( "32 - 8 = 24 cubes are left that will have exactly 2 sides painted. \n" ); document.write( "----- \n" ); document.write( "that makes your answer = 24. \n" ); document.write( "----- \n" ); document.write( "another way to look at this is to look at each side of your cube. \n" ); document.write( "there are 16 faces of cubes on each side. \n" ); document.write( "out of those 16 only the on the edge of each side of the cube and not on the corners are the candidates for having 2 faces painted. \n" ); document.write( "there are 8 of these faces on each side of the cube that will have a companion face on the other side of the cube only. \n" ); document.write( "6 sides of the cube times 8 = 48 faces thaat are painted that are members of the set of 2 faces to a cube. \n" ); document.write( "48 / 2 = 24 again. \n" ); document.write( "----- \n" ); document.write( "i would say 24 cubes is your answer. \n" ); document.write( "----- \n" ); document.write( "a picture of your cubes can be seen on this website. \n" ); document.write( "http://theo.x10hosting.com/ \n" ); document.write( "----- \n" ); document.write( "go there and click on 206586. \n" ); document.write( "---- \n" ); document.write( "if it's not there, give it 1/2 hour and try again.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |