document.write( "Question 30688: the time required to finish a mathematics test varies directly as the number of problems on the test and inversely as the number of hours spent studying. If a 50-problems test can be completed in 2 hours after 3 hours of studying, how long would a 75-problem test take after 4 hours of studying? \n" ); document.write( "

Algebra.Com's Answer #17422 by Paul(988) $\"\"$ $\"About$

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Let the time be x
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document.write( "In first equation:
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document.write( "2x+3x=50
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document.write( "5x=50
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document.write( "x=10
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document.write( "Subsitute it into second equation:
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document.write( "4(10)+10x=75
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document.write( "10x=75-40
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document.write( "10x=35
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document.write( "x=3.5
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document.write( "Hence, it requires a test of 3.5hours.
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document.write( "Paul. \n" );
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