document.write( "Question 982656: in a quiz game of 20 questions, each correct answer earns 5 points. Each incorrect answer reduces the score by 2 points. Omitted questions scored 0 points. Jana has a total score of 59 points. How many questions did she omit? \n" ); document.write( "
Algebra.Com's Answer #802617 by greenestamps(13219) You can put this solution on YOUR website! \n" ); document.write( "A quick informal solution using logical reasoning and some simple mental arithmetic -- if a formal algebraic solution is not required. \n" ); document.write( "Each correct answer earns 5 points; the total points earned for the correct answers is a multiple of 5. \n" ); document.write( "Each incorrect answer loses 2 points; the total points lost for the correct answers is an even number. \n" ); document.write( "Jana's score was 59, an odd number. That means the number of correct answers has to be odd, making the total for the correct answers an odd multiple of 5 -- that is, a number with units digit 5. \n" ); document.write( "So 59 has to be some even number less than a number with units digit 5. \n" ); document.write( "The first possibility is 59 = 65-6, which means 13 correct answers an 3 wrong answers. \n" ); document.write( "The next possibility is 59 = 75-16; but that requires far more than 20 questions on the test. \n" ); document.write( "ANSWER: 13 right, 3 wrong; that means 4 questions were unanswered. \n" ); document.write( " \n" ); document.write( " |