document.write( "Question 668449: Jessica has a chance to win $10,000 if she can spend exactly $10089 on 750 boxes of candy, some of which sell for $9 and others that sell for $16 a box. How many boxes of candy does Jessica choose in order for her to qualify for the $10,000 prize? \n" ); document.write( "
Algebra.Com's Answer #415563 by DrBeeee(684)\"\" \"About 
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This is the same as a coin problem.
\n" ); document.write( "Let a = number of boxes @ $9
\n" ); document.write( "Let b = number of boxes @ $16
\n" ); document.write( "Then we have
\n" ); document.write( "(1) a + b = 750 and
\n" ); document.write( "(2) 9*a + 16*b = 10089
\n" ); document.write( "Put (1) into (2) and get
\n" ); document.write( "(3) 9*(750 - b) + 16*b = 10089 or
\n" ); document.write( "(4) 6750 - 9*b + 16*b = 10089 or
\n" ); document.write( "(5) 7*b = 3339 or
\n" ); document.write( "(6) b = 477 and from (1) we have
\n" ); document.write( "(7) a = 273
\n" ); document.write( "To check these values use (2).
\n" ); document.write( "Is (9*273 + 16*477 = 10089)?
\n" ); document.write( "Is (2457 + 7632 = 10089)?
\n" ); document.write( "Is (10089 = 10089)? Yes
\n" ); document.write( "Answer: Jessica needs to sell 273 of the $9 boxes of candy and 477 of the $16 boxes of candy to get a total sales of $10,089.
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