document.write( "Question 60618: Joe has been collecting dimes and quarters all year. Now he wants to buy a present for his wife, so he opens his piggy bank. He has 479 coins. When the bank puts them through its counting machine, it tells him he has $72.50. How many dimes and how many quarters does he have? \n" ); document.write( "

Algebra.Com's Answer #41608 by uma(370) $\"\"$ $\"About$

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Let Joe have x dimes and y quarters.
\n" ); document.write( "Then x + y = 479 ---------(1) [since he had 479 coins]\r
\n" ); document.write( "\n" ); document.write( "Value of x dimes = 10x cents
\n" ); document.write( "Value of y quarters = 25y cents\r
\n" ); document.write( "\n" ); document.write( "Total value = 10x + 25y\r
\n" ); document.write( "\n" ); document.write( "==> 10x + 25y = 7250 cents [he totally had $72.50]
\n" ); document.write( "==> 10x + 25y = 7250 ------------------(2)\r
\n" ); document.write( "\n" ); document.write( "Multiplying (1) by 10 we get..
\n" ); document.write( "10x + 10y = 4790
\n" ); document.write( "10x + 25y = 7250 --------(2)\r
\n" ); document.write( "\n" ); document.write( "Subtracting the above two equations, we get
\n" ); document.write( "- 15y = -2460
\n" ); document.write( "==> -15y/-15 = -2460/-15
\n" ); document.write( "==> y = 164
\n" ); document.write( "Plugging in this value in (1) ,
\n" ); document.write( "x + 164 = 479
\n" ); document.write( "==> x = 479 - 164 [Subtracting 164 from both the sides ]
\n" ); document.write( "==> x = 315\r
\n" ); document.write( "\n" ); document.write( "So Joe had 315 dimes and 164 quarters.\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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