document.write( "Question 204859: I have a plate of WHOLE cookies; I gave Jodie half of what was on the plate, plus half of a cookie. I gave Beth half of what was left on the plate, plus half of a cookie; I gave Michelle half of what was left on the plate, plus half of a cookie. There are no cookies left, and I didn’t break any in half. How many cookies were on the plate to begin with? \n" ); document.write( "
Algebra.Com's Answer #154614 by Earlsdon(6294)\"\" \"About 
You can put this solution on YOUR website!
Well, I tried 7 cookies and that seems to work, and I know that this is not an algebraic answer, but I think that it can be worked out.
\n" ); document.write( "Start with 7.
\n" ); document.write( "To Jodie, half of 7 is 3.5 plus 0.5 = 4 so there are 3 cookies left.
\n" ); document.write( "To Beth, half of 3 is 1.5 pus 0.5 = 2, so now there is 1 cookie left.
\n" ); document.write( "To Michelle, half of 1 is 0.5 plus o.5 = 1, no more cookies left and no cookies needed to be broken.
\n" ); document.write( "----------------------------------------------------------------------
\n" ); document.write( "How did I get 7? Read on!
\n" ); document.write( "Let x = the original number of whole cookies on the plate.
\n" ); document.write( "To Jodie, you gave:
\n" ); document.write( "\"%28x%2F2+%2B+1%2F2%29\" what was left after that can be expressed by:
\n" ); document.write( "\"x-%28x%2F2%2B1%2F2%29\" let's call this quantity y, so...
\n" ); document.write( "\"y+=+%28x-%28x%2F2%2B1%2F2%29%29\"
\n" ); document.write( "To Beth, you gave:
\n" ); document.write( "\"%28y%2F2%2B1%2F2%29\" what was left after that can be expressed by:
\n" ); document.write( "\"y-%28y%2F2%2B1%2F2%29\" let's call this quantity z, so...
\n" ); document.write( "\"z+=+%28y-%28y%2F2%29%2B1%2F2%29\"
\n" ); document.write( "To Michelle, you gave:
\n" ); document.write( "\"z%2F2%2B2%2F2\" what was left after that can be xepressed by:
\n" ); document.write( "\"z-%28z%2F2%2B1%2F2%29\"...and, because there were no cookies left, we'll call this zero, so...
\n" ); document.write( "\"z-%28z%2F2%2B1%2F2%29+=+0\" Now we can solve this for z: First simplify it.
\n" ); document.write( "\"%282z-z-1%29%2F2+=+0\" Multiply both sides by 2.
\n" ); document.write( "\"z-1+=+0\" Add 1 to both sides.
\n" ); document.write( "\"highlight%28z+=+1%29\" Now we know z, we can solve for y.
\n" ); document.write( "\"1+=+%28y-%28y%2F2%2B1%2F2%29%29\"
\n" ); document.write( "\"%282y-y-1%29%2F2+=+1\"
\n" ); document.write( "\"y-1+=+2\"
\n" ); document.write( "\"highlight%28y+=+3%29\" Finally, we can solve for x, the original number of cookies.
\n" ); document.write( "\"3+=+%28x-%28x%2F2%2B1%2F2%29%29\"
\n" ); document.write( "\"%282x-x-1%29%2F2+=+3\"
\n" ); document.write( "\"x-1+=+6\"
\n" ); document.write( "\"highlight%28x+=+7%29\"\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );