document.write( "Question 563036: Bill has 10 coins, all of which are dimes and quarters. If his dimes were quarters and his quarters were dimes, his coins would total 30 cents more. How many quarters does Bill have? \n" ); document.write( "
Algebra.Com's Answer #364743 by htmentor(1343)\"\" \"About 
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Bill has 10 coins, all of which are dimes and quarters. If his dimes were quarters and his quarters were dimes, his coins would total 30 cents more. How many quarters does Bill have?
\n" ); document.write( "Let d = the number of dimes
\n" ); document.write( "Then 10 - d = the number of quarters
\n" ); document.write( "Let the original total = T
\n" ); document.write( "Then T = 10d + 25(10-d)
\n" ); document.write( "This gives T = 250 - 15d [1]
\n" ); document.write( "If the coins are reversed the total is 30 cents more:
\n" ); document.write( "T + 30 = 10(10-d) + 25d
\n" ); document.write( "This gives T = 70 + 15d [2]
\n" ); document.write( "Subtract [2] from [1]:
\n" ); document.write( "0 = 180 - 30d
\n" ); document.write( "This gives d = 6
\n" ); document.write( "So he has 10 - 6 = 4 quarters
\n" ); document.write( "Check:
\n" ); document.write( "6*10 + 4*25 = 160
\n" ); document.write( "4*10 + 6*25 = 190 [30 cents more]\r
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