document.write( "Question 81742: Adult tickets for a play cost $10 and child tickets cost $3. If there were 25 people at a performance and the theater collected $110 from ticket sales, how many adults and how many children attended the play?\r
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\n" ); document.write( " ___________ adults attended the play
\n" ); document.write( " ___________ children attended the play\r
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Algebra.Com's Answer #58567 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
There are two unknowns in this problem ... the number of adults and the number of children
\n" ); document.write( "that attend a play. This is a clue that you will need two equations to solve this problem.
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\n" ); document.write( "As a start, let A represent the number of adults and C represent the number of children.
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\n" ); document.write( "The problem tells you that 25 people attend the performance. This tells you that if you
\n" ); document.write( "add the number of adults and the number of children that attend, you should get an answer of 25.
\n" ); document.write( "In equation form this becomes:
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\n" ); document.write( "A + C = 25
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\n" ); document.write( "This is the first of the two equations.
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\n" ); document.write( "Next you can determine the amount of money taken in from adult tickets and also from children's
\n" ); document.write( "tickets. Since adult tickets are $10 each, the amount of money taken in from the sale of
\n" ); document.write( "adult tickets is $10 times the number of adults that attend or 10*A. Similarly, since
\n" ); document.write( "children's tickets are $3 each, the amount of money from the sale of children's tickets is
\n" ); document.write( "$3 times the number of children that attend or 3*C. The problem tells you that the total
\n" ); document.write( "amount from the sale of tickets is $110. In equation form this becomes:
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\n" ); document.write( "10*A + 3*C = 110
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\n" ); document.write( "This is the second equation that we need.
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\n" ); document.write( "The equations can be solved by substitution. Since the problem asks for the number of
\n" ); document.write( "children that attend the play, it would help if the second equation were converted so
\n" ); document.write( "that it contained only the variable C. You can do that by solving the first equation
\n" ); document.write( "for A in terms of C. Start with the first equation:
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\n" ); document.write( "A + C = 25
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\n" ); document.write( "Subtract C from both sides to get:
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\n" ); document.write( "A = 25 - C
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\n" ); document.write( "Then in the second equation you can substitute 25 - C for A. If you do that the second
\n" ); document.write( "equation becomes:
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\n" ); document.write( "10*(25 - C) + 3*C = 110
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\n" ); document.write( "Do the distributed multiplication on the left side to get:
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\n" ); document.write( "250 - 10*C + 3*C = 110
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\n" ); document.write( "On the left side combine the two terms that contain C and the equation becomes:
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\n" ); document.write( "250 - 7*C = 110
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\n" ); document.write( "Now subtract 250 from both sides so that only the term involving C remains on the left
\n" ); document.write( "side. The subtraction of 250 from both sides results in:
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\n" ); document.write( "- 7*C = 110 - 250 = - 140
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\n" ); document.write( "Finally, divide both sides by -7, the multiplier of C. When you do that you get:
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\n" ); document.write( "C = 20
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\n" ); document.write( "So 20 children attend. (This means that of the 25 that attend 20 are children and the
\n" ); document.write( "remaining 5 are adults.)
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\n" ); document.write( "As a check, at $3 each for the 20 children's tickets, 3*20 equals $60 is taken in from
\n" ); document.write( "the sales of childrens tickets. And at $10 each for the 5 adults that attend, the income
\n" ); document.write( "from the sale of adult tickets is 10*5 = $50. Therefore, the total income from the sale
\n" ); document.write( "of tickets is $60 + $50 = $110. That is exactly what it is supposed to be, so our answer
\n" ); document.write( "checks out. 20 children attend the play and 5 adults attend.
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\n" ); document.write( "Hope this helps you to understand the problem ... and how to get and solve the pair of
\n" ); document.write( "equations that is needed.
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