document.write( "Question 67717: Here is the problem. A parts person has to spend exactly $100 and must buy 100 parts. Good parts cost 5$, regular parts cost 1$, and cheap parts cost 25 cents. He has to buy 100 parts for $100 and have some of each part. I tried the trial and error method and got an answer, but wanted to get an anwer algebraically, (sp?)
\n" ); document.write( " I tried: 5x + y + .25z = $100
\n" ); document.write( " x + y + z = 100 and substituting variables but could not get it to work. I appreciate your help.
\n" ); document.write( " George \n" ); document.write( "
Algebra.Com's Answer #48177 by ankor@dixie-net.com(22740)\"\" \"About 
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A parts person has to spend exactly $100 and must buy 100 parts. Good parts cost 5$, regular parts cost 1$, and cheap parts cost 25 cents. He has to buy 100 parts for $100 and have some of each part.
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\n" ); document.write( "Let the three types of parts = x, y, z
\n" ); document.write( "Three unknowns, two equations calls for some assumptions
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\n" ); document.write( "We know that the $5 part (x) has to be 4 or less,
\n" ); document.write( " lets assume x = 3 good parts at $5 ea
\n" ); document.write( ":
\n" ); document.write( "3 + y + z = 100
\n" ); document.write( "y + z = 97
\n" ); document.write( "and:
\n" ); document.write( "3(5) + y + .25z = 100
\n" ); document.write( "15 + y + .25z = 100
\n" ); document.write( "y + .25z = 85
\n" ); document.write( ":
\n" ); document.write( "See if these two equations will give an integer answer for z
\n" ); document.write( "y + z = 97
\n" ); document.write( "y + .25z = 85
\n" ); document.write( "-------------- subtract
\n" ); document.write( ".75z = 12
\n" ); document.write( "z = 12/.75
\n" ); document.write( "z = 16 ea cheap parts\r
\n" ); document.write( "\n" ); document.write( "Find y from the equation y + z = 97
\n" ); document.write( "y + 16 = 97
\n" ); document.write( "y = 97 - 16
\n" ); document.write( "y = 81 ea regular parts
\n" ); document.write( ":
\n" ); document.write( "we have 3 good, 81 regular and 16 cheap parts
\n" ); document.write( ":
\n" ); document.write( "Check in the cost equation:
\n" ); document.write( "3(5) + 81 + .25(16) =
\n" ); document.write( "15 + 81 + 4 = $100
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