document.write( "Question 705081: Thirty students took a test.The average grade for the whole class was 70 and the average of the twenty who passed was 80.What was the average of the one who failed? \n" ); document.write( "

Algebra.Com's Answer #434409 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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Thirty students took a test.
\n" ); document.write( "The average grade for the whole class was 70 and the average of the twenty who passed was 80.
\n" ); document.write( "What was the average of the one who failed?
\n" ); document.write( ":
\n" ); document.write( "f = the average of the 10 that failed
\n" ); document.write( " $\"%2810f+%2B+20%2880%29%29%2F30\"$ = 70
\n" ); document.write( "multiply both sides by 30
\n" ); document.write( "10f + 1600 = 30(70)
\n" ); document.write( "10f = 2100 - 1600
\n" ); document.write( "10f = 500
\n" ); document.write( "f = 500/10
\n" ); document.write( "f = 50 is the av of the 10 that failed
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check this
\n" ); document.write( " $\"%28500%2B1600%29%2F30\"$ = 70
\n" ); document.write( " \n" ); document.write( "

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