document.write( "Question 115451: Anna has 12 bills in her wallet, some $5 and some $10. The total value of the bills is $100. How many of each bill does Anna have? \n" ); document.write( "
Algebra.Com's Answer #84011 by ganesh(20)\"\" \"About 
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Let Anna has x number of $5 bills and y number of $10 bills.
\n" ); document.write( "Totally, there are 12 bills.
\n" ); document.write( "Therefore, x + y = 12---------(1).
\n" ); document.write( "The value of $5 bills = 5*x = 5x.
\n" ); document.write( "The value of $10 bills = 10*y = 10y
\n" ); document.write( "So, the total value of the bills = 5x + 10y.
\n" ); document.write( "It is given that the total value of the bills = $100.
\n" ); document.write( "Therefore, 5x + 10y = 100.
\n" ); document.write( "That is, x + 2y = 20-----------(2).\r
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\n" ); document.write( "\n" ); document.write( "Solve (1) and (2).\r
\n" ); document.write( "\n" ); document.write( "(1)*2 gives, 2x + 2y = 24------(3)
\n" ); document.write( "(2) gives x + 2y = 20-------(2)\r
\n" ); document.write( "\n" ); document.write( "(3) - (2) x = 4
\n" ); document.write( "Plug in x = 4 in (1), we get y = 8.\r
\n" ); document.write( "\n" ); document.write( "So, Anna has 4 bills of $5 and 8 bills of $10
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