document.write( "Question 772918: Two high school classes took the same test. One class of 20 students made an average grade of 80%; the other class had an average grade of 70%. If the average grade for the combined classes was 74%, how many people were in the second class? \n" ); document.write( "

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Two high school classes took the same test. One class of 20 students made an average grade of 80%; the other class had an average grade of 70%. If the average grade for the combined classes was 74%, how many people were in the second class?
\n" ); document.write( "***
\n" ); document.write( "let x=number of students in the 2nd class
\n" ); document.write( "In the first class 20 students had a cumulative score=20*80=1600
\n" ); document.write( "In the 2nd class x number of students had a cumulative score=x*70
\n" ); document.write( "combined classes had a combined cumulative score=1600+70x
\n" ); document.write( "20+x=total number of students in both classes
\n" ); document.write( "..
\n" ); document.write( " $\"%2820%2A80%2B70x%29%2F%2820%2Bx%29=74\"$
\n" ); document.write( " $\"1600%2B70x=1480%2B74x\"$
\n" ); document.write( "4x=120
\n" ); document.write( "x=30
\n" ); document.write( "how many people were in the second class? 30 \n" ); document.write( "

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