document.write( "Question 1113041: A student loses a mark for every wrong answer and scores 2 marks for every correct answer. If the answers all the 60 questions in an exam. and secure 39 marks, how many of them were correct \n" ); document.write( "

Algebra.Com's Answer #728106 by ikleyn(52803) $\"\"$ $\"About$

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\n" ); document.write( "1. - Two equations setup and solution\r
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document.write( " x + y = 60       (1)\r\n" );
document.write( "2x - y = 39       (2)\r\n" );
document.write( "---------------------------Add eq(1) and (2) to eliminate y. You will get\r\n" );
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document.write( "3x = 60+39 = 99    ====>  x =  = 33.\r\n" );
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document.write( "Answer.  33 correct answers.  The rest  60-33 = 27 answers are incorrect.\r\n" );
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document.write( "Check.   2*33 - 27 = 39.    ! OK !\r\n" );
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\n" ); document.write( "\n" ); document.write( "2 - One equation setup and solution\r
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document.write( "2x - (60-x) = 39.\r\n" );
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document.write( "3x = 39 + 60 = 99  ====>  x =  = 33 the same answer.\r\n" );
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