document.write( "Question 323539: Please help me solve this equation\r
\n" ); document.write( "\n" ); document.write( "Shane has pennies, dimes, and quarters. He has a total of $17.64. He has twice as many quarters as dimes and one-third as many dimes as pennies. How many of each coin does he have?
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Algebra.Com's Answer #231577 by jessica43(140)\"\" \"About 
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To solve this problem you are going to write three equations using the given information.
\n" ); document.write( "First,you know that the total value of Shane's money is $17.64 and the value of a penny is $0.01, a dime is $0.10 and a quarter is $0.25:
\n" ); document.write( "0.01(P) + 0.10(D) + 0.25(Q) = 17.64 (P = number of pennies, D= number of dimes, Q= number of quarters)
\n" ); document.write( "Second, you know that Shane has twice as many quarters as dimes:
\n" ); document.write( "Q = 2(D)
\n" ); document.write( "Finally, you know that he has one-third as many dimes as pennies:
\n" ); document.write( "D = (1/3)P
\n" ); document.write( "You can also rewrite this as P = 3(D)
\n" ); document.write( "Now to solve this problem you want to plug in the second and third equations into the first equation. Since the variable D is found in all three equations, we want that to be the remaining variable we solve for. That means, plug in the other equations to replace the Q and the P:
\n" ); document.write( "0.01(P) + 0.10(D) + 0.25(Q) = 17.64
\n" ); document.write( "0.01(3D) + 0.10(D) + 0.25(2D) = 17.64
\n" ); document.write( "0.03D + 0.10D + 0.5D = 17.64
\n" ); document.write( "0.63D = 17.64
\n" ); document.write( "D = 28
\n" ); document.write( "Now plug in this value into the first equation to solve for Q:
\n" ); document.write( "Q = 2D
\n" ); document.write( "Q = 2(28)
\n" ); document.write( "Q = 56
\n" ); document.write( "Now plug in this value into the second equation to solve for P:
\n" ); document.write( "P = 3D
\n" ); document.write( "P = 3(28)
\n" ); document.write( "P = 84
\n" ); document.write( "So Shane has 28 dimes, 56 quarters and 84 pennies.
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