document.write( "Question 531054: A chlds bank contains $6.30 in dimes and quarters. There are twice as many dimes as quarters. How many of each kind of coin are in the bank? \n" ); document.write( "

Algebra.Com's Answer #350317 by oberobic(2304) $\"\"$ $\"About$

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With coin problems you need to keep track of the count of the coins and the value.
\n" ); document.write( "d = number of dimes
\n" ); document.write( "10d = value of the dimes in cents
\n" ); document.write( "q = number of quarters
\n" ); document.write( "25q = value of the quarters in cents
\n" ); document.write( ".
\n" ); document.write( "10d + 25q = 630 cents
\n" ); document.write( ".
\n" ); document.write( "d = 2q
\n" ); document.write( ".
\n" ); document.write( "substitute
\n" ); document.write( ".
\n" ); document.write( "10(2q) + 25q = 630
\n" ); document.write( "20q + 25q = 630
\n" ); document.write( "45q = 630
\n" ); document.write( "q = 14
\n" ); document.write( ".
\n" ); document.write( "d = 2q
\n" ); document.write( "d = 2*14 = 28
\n" ); document.write( ".
\n" ); document.write( "Check the values to be sure this answer is right.
\n" ); document.write( "25(14) = 350 cents
\n" ); document.write( "10(28) = 280 cents
\n" ); document.write( "total = 630 cents
\n" ); document.write( "Correct.
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\n" ); document.write( "Answer: The child has 14 quarters and 28 dimes.
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\n" ); document.write( "Done. \n" ); document.write( "

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