document.write( "Question 1210613: Marek and Zaven had 900 coins altogether. Marek spent 25% fewer coins than Zaven. Zaven was left with 50% as many coins as the number he spent. Marek had 75% of the total number of coins the two friends had left in the end. How many coins did Marek have in the end?
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Algebra.Com's Answer #854420 by greenestamps(13351) You can put this solution on YOUR website! \n" ); document.write( "After working a short way through the problem, I chose to set the problem up like this, to make the work easier by avoiding having to work with fractions or decimals. \n" ); document.write( "Marek spent 25% fewer coins than Zaven -- i.e., he spent three-fourths as many as Zaven. So \n" ); document.write( "Let 4x = # Zaven spent \n" ); document.write( "Then 3x = # Marek spent \n" ); document.write( "The number Zaven left with was half the number he spent. So \n" ); document.write( "2x = # Zaven was left with; and then \n" ); document.write( "4x+2x = 6x = # Zaven started with \n" ); document.write( "The total number of coins the two of them had is 900, so \n" ); document.write( "900-6x = # Marek started with \n" ); document.write( "Then \n" ); document.write( "(90-6x)-3x = 900-9x = # Marek finished with \n" ); document.write( "In the end, Marek had 3/4 of the total number of coins. Here we have two (at least) ways to continue; we could either say that the number Marek finished with is 3/4 of the total 900, or we could say Marek finished with 3 times as many as Zaven. For an unknown reason, I chose the second option when I first worked the problem all the way through. \n" ); document.write( "900-9x = 3(2x) \n" ); document.write( "900-9x = 6x \n" ); document.write( "900 = 15x \n" ); document.write( "x = 900/15 = 60 \n" ); document.write( "The problem asks for the number Marek finished with. \n" ); document.write( "ANSWER: 900-9x = 900-540 = 360 \n" ); document.write( " \n" ); document.write( " |