document.write( "Question 1143081: 100 students enter a competition. The average score for the entire group is 63. The average score for male students is 60 and average score for female students is 70. Question: What is the difference in number of male and female students? \n" ); document.write( "
Algebra.Com's Answer #763853 by greenestamps(13215) You can put this solution on YOUR website! \n" ); document.write( "Here is a very non-traditional, non-algebraic method for solving this problem. \n" ); document.write( "Note that this is essentially a mixture problem -- you are mixing scores with an average of 60% with scores with an average of 70% and getting an overall average of 63%. \n" ); document.write( "To solve a mixture problem like this, you can consider the three percentages on a number line; where the average lies between the two percentages exactly determines the numbers of students with each average. \n" ); document.write( "Here is all that is needed to solve the problem with this method: \n" ); document.write( "63% is 3/10 of the way on the number line from 60% to 70%; that means 3/10 of the students are in the higher average group. \n" ); document.write( "That's it! One line with rather simple calculations. \n" ); document.write( "With 100 students, that means 30 students are in the 70% average group, so the other 70 are in the 60% average group. \n" ); document.write( "ANSWER: 30 female students and 70 male students; a difference of 40. \n" ); document.write( " |