document.write( "Question 168521: A jar containing pennies, nickels and dimes is worth $8.40. The number of
\n" ); document.write( "dimes is six less than twice the number of pennies and there is an equal
\n" ); document.write( "number of dimes and nickels. How many nickels are in the jar. \n" ); document.write( "

Algebra.Com's Answer #124223 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"p\"$ = the number of pennies
\n" ); document.write( "Let $\"n\"$ = the number of nickels
\n" ); document.write( "Let $\"d\"$ = the number of dimes
\n" ); document.write( "Given:
\n" ); document.write( "(1) $\"p+%2B+5n+%2B+10d+=+840\"$ (in cents)
\n" ); document.write( "(2) $\"d+=+2p+-+6\"$
\n" ); document.write( "(3) $\"d+=+n\"$
\n" ); document.write( "------------
\n" ); document.write( "From (2),
\n" ); document.write( " $\"2p+-+6+=+d\"$
\n" ); document.write( " $\"2p+=+d+%2B+6\"$
\n" ); document.write( " $\"p+=+%281%2F2%29%2Ad+%2B+3\"$
\n" ); document.write( "Substitute in (1)
\n" ); document.write( " $\"p+%2B+5n+%2B+10d+=+840\"$
\n" ); document.write( " $\"%281%2F2%29%2Ad+%2B+3+%2B+5d+%2B+10d+=+840\"$
\n" ); document.write( " $\"%281%2F2%29%2Ad+%2B+15d+%2B+3+=+840\"$
\n" ); document.write( "Multiply both sides by $\"2\"$
\n" ); document.write( " $\"d+%2B+30d+%2B+6+=+1680\"$
\n" ); document.write( " $\"31d+=+1674\"$
\n" ); document.write( " $\"d+=+54\"$
\n" ); document.write( " $\"n+=+54\"$
\n" ); document.write( "There are 54 nickels in the jar
\n" ); document.write( "Also,
\n" ); document.write( " $\"p+=+%281%2F2%29%2Ad+%2B+3\"$
\n" ); document.write( " $\"p+=+%281%2F2%29%2A54+%2B+3\"$
\n" ); document.write( " $\"p+=+30\"$
\n" ); document.write( "Now check answer:
\n" ); document.write( " $\"p+%2B+5n+%2B+10d+=+840\"$
\n" ); document.write( " $\"30+%2B+5%2A54+%2B+10%2A54+=+840\"$
\n" ); document.write( " $\"30+%2B+270+%2B+540+=+840\"$
\n" ); document.write( " $\"840+=+840\"$
\n" ); document.write( "OK \n" ); document.write( "

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