document.write( "Question 174573: 500 students are enrolled in at least two of these three classes: Math, English, and History. 170 are enrolled in both Math and English, 150 are enrolled in both History and English, and 300 are enrolled in Math and History. How many of the 500 students are enrolled in all three?
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Algebra.Com's Answer #129639 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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500 students are enrolled in at least two of these three classes: Math,
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\n" ); document.write( " 150 are enrolled in both History and English, and 300 are enrolled in
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\n" ); document.write( "How many of the 500 students are enrolled in all three?
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\n" ); document.write( "Let x = no. students enrolled in all three
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\n" ); document.write( "These students are represented in an equal amt in all three groups:
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\n" ); document.write( "The equation for students taking only two subjects
\n" ); document.write( "(170-x) + (150-x) + (300-x) = 500 - x
\n" ); document.write( "620 - 3x + x = 500
\n" ); document.write( "-2x = 500 - 620
\n" ); document.write( "-2x = -120
\n" ); document.write( "x = +60 students take all three subjects
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\n" ); document.write( "170 - 60 = 110 students taking Math & Eng only
\n" ); document.write( "150 - 60 = 90 students taking Hist & Eng only
\n" ); document.write( "300 - 60 = 240 students taking Math & Hist only
\n" ); document.write( "All 3 sub = 60 students
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\n" ); document.write( "Tot stud =500
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