document.write( "Question 1149313: In a class of 36 students 25 study chemistry and 22 study mathematics and 25
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Algebra.Com's Answer #770695 by math_helper(2461)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Using the same interpretation as tutor @greenestamps, and borrowing the nice Venn diagram code from tutor @Edwin_M, and adding my own lettering:\r
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document.write( "a = Chem only
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document.write( "b = Chem & Math only
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document.write( "c = Math only
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document.write( "d = all 3 subjects
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document.write( "e = Chem & Phys only
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document.write( "f = Math & Phys only
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document.write( "g = Phys only\r
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document.write( "There are 7 equations in 7 unknowns:\r
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document.write( "1. a+c+g = 15
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document.write( "2. e+d = 18
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document.write( "3. f+d = 17
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document.write( "4. a+b+d+e = 25
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document.write( "5. c+b+d+f = 22
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document.write( "6. d+e+f+g = 25
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document.write( "7. a+b+c+d+e+f+g = 36\r
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document.write( "Which has the solution (courtesy of http://www.bluebit.gr/matrix-calculator/solve.aspx):\r
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document.write( "a = 6
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document.write( "b = 1     <<< Taking Math & Chem only
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document.write( "c = 4
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document.write( "d = 15    <<< Taking all 3 subjects
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document.write( "e = 3
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document.write( "f = 2
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document.write( "g = 5  \r
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document.write( "This agrees with tutor @greenestamps answer.  Tutor @Edwin_McCrary has a at least one setup problem that I noticed: (referring to his diagrams)  e + g + i = 15 should be d + f + j = 15.\r
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document.write( "Best wishes.
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