document.write( "Question 152016: A cube of white chalk is painted red and cut parallel to a pair of parallel size to form two rectangular solid of equal volume. What percentage of the surface area of each of the new solid is not painted red.
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Algebra.Com's Answer #111783 by jojo14344(1513) $\"\"$ $\"About$

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Answer: 20% of surface area of each is not painted
\n" ); document.write( "Proof:
\n" ); document.write( "Before it was cut into half, all the sides are equal right? (a cube is a square with 3-D body). Then it was cut to half and became a rectangular solid. One side of which is not painted.
\n" ); document.write( "We have to remember $\"Surface+Area\"$ of a rectangular solid:
\n" ); document.write( " $\"SA=2LH%2B2LW%2B2WH\"$ ---------------------> EQN 1
\n" ); document.write( "Important: before it has ALL SIDES EQUAL, and when cut into half there appears now the $\"Length\"$ and the $\"Width\"$ ----> the dimensions of the $\"Width\"$ now will be half of the $\"Length\"$ : $\"W=%281%2F2%29L\"$ , Also the $\"Height\"$ remains the same as the $\"Length\"$ . Only the $\"Width\"$ changed when cut into half.
\n" ); document.write( "For the $\"Area\"$ of the new rectangular solid, since one side is NOT painted, $\"SA%5Bnew%5D=2LH%2B1LW%2B2WH\"$ -------------------> EQN 2
\n" ); document.write( "NOW, IF YOU PLUG IN VALUES IN EQN 1 AND EQN 2, REMEMBER $\"L=H\"$ , $\"W=%281%2F2%29%0D%0AL\"$ and make $\"%28EQN2%2FEQN%29-1%29\"$ . Get ABSOLUTE VALUE (no negative)*100% ----------> PERCENTAGE of Surface Area NOT painted.
\n" ); document.write( "Hope this helps.
\n" ); document.write( "Thank you,
\n" ); document.write( "Jojo
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