document.write( "Question 153438: A jar contains 40 Coins consisting of dimes and quarters and having a total value of $4.90. How many of each coin are there? \n" ); document.write( "

Algebra.Com's Answer #112951 by jojo14344(1513) $\"\"$ $\"About$

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\n" ); document.write( "Number of dimes = $\"x\"$
\n" ); document.write( "Number of quarters = $\"y\"$
\n" ); document.write( "So, $\"x%2By=40coins\"$ ----------------------------------------> eqn 1
\n" ); document.write( "Also,
\n" ); document.write( " $\"0.10x%2B0.25y=4.90\"$ ---------------------------------------> eqn 2
\n" ); document.write( "In eqn 1 we get, $\"y=40-x\"$ , substitute this in eqn 2:
\n" ); document.write( " $\"0.10x%2B0.25%2840-x%29=4.90\"$
\n" ); document.write( " $\"0.10x%2B10-0.25x=4.90\"$
\n" ); document.write( " $\"10-4.90=0.25x-0.10x\"$
\n" ); document.write( " $\"5.10=0.15x\"$ --------> $\"cross%285.10%2934%2Fcross%280.15%29=cross%280.15%29%2Ax%2Fcross%280.15%29\"$
\n" ); document.write( " $\"x=34\"$ --------------------------------------> no. of dimes
\n" ); document.write( "In eqn 1:
\n" ); document.write( " $\"34%2By=40\"$ --> $\"y=40-34=6\"$ ----------------> no. quarters
\n" ); document.write( "In doubt? Go back eqn 2:
\n" ); document.write( " $\"0.10%2834%29%2B0.25%286%29=4.90\"$
\n" ); document.write( " $\"3.40%2B1.50=4.90\"$
\n" ); document.write( " $\"4.90=4.90\"$
\n" ); document.write( "Thank you,
\n" ); document.write( "Jojo \n" ); document.write( "

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