document.write( "Question 323609: The average age of boys & girls in a class is 10.5 yrs. That of the boys is 10.6 & that of the girls is 10.1. If there are 60 boys in the class how many girls are there? \n" ); document.write( "

Algebra.Com's Answer #231556 by mananth(16946) $\"\"$ $\"About$

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let the number of girls be x
\n" ); document.write( "Number of boys = 60
\n" ); document.write( "Total students = x+60
\n" ); document.write( "Average age of class = 10.5
\n" ); document.write( "The total age of the class = 10.5(x+60)
\n" ); document.write( "..
\n" ); document.write( "Average age of girls = 10.1
\n" ); document.write( "total age of girls = 10.1x
\n" ); document.write( "..
\n" ); document.write( "Average age of boys = 10.6
\n" ); document.write( "Number of boys = 60
\n" ); document.write( "Total age of boys = 10.6*60= 636 years
\n" ); document.write( "..
\n" ); document.write( "Total age of girls + total age of boys = Total age of class
\n" ); document.write( "10.1x+636=10.5(x+60)
\n" ); document.write( "10.1x +636=10.5x + 630
\n" ); document.write( "10.5x-10.1x = 636-630
\n" ); document.write( "0.4x= 6
\n" ); document.write( "x= 6/0.4
\n" ); document.write( "Multiply by 10 and divide by 10
\n" ); document.write( "x=60/4
\n" ); document.write( "x=15 girls \n" ); document.write( "

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