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 #231559 by Fombitz(32388) $\"\"$ $\"About$

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Let B be the sum of ages of the boys, G sum of ages of the girls.
\n" ); document.write( "Let Nb be the number of boys, Ng be the number of girls.
\n" ); document.write( "1. $\"B%2FNb=10.6\"$
\n" ); document.write( "2. $\"G%2FNg=10.1\"$
\n" ); document.write( "3. $\"%28B%2BG%29%2F%28Nb%2BNg%29=10.5\"$
\n" ); document.write( " $\"Nb=60\"$
\n" ); document.write( "Then from eq. 1,
\n" ); document.write( " $\"B=60%2810.6%29\"$
\n" ); document.write( " $\"B=636\"$
\n" ); document.write( "From eq. 2,
\n" ); document.write( " $\"G=10.1%2ANg\"$
\n" ); document.write( "Substitute into eq. 3,
\n" ); document.write( " $\"%28B%2BG%29%2F%28Nb%2BNg%29=10.5\"$
\n" ); document.write( " $\"B%2BG=10.5%2ANb%2B10.5%2ANg\"$
\n" ); document.write( " $\"B%2B10.1%2ANg=10.5%2ANb%2B10.5%2ANg\"$
\n" ); document.write( " $\"10.6%2ANb%2B10.1%2ANg=10.5%2ANb%2B10.5%2ANg\"$
\n" ); document.write( " $\"0.1%2ANb=0.4%2ANg\"$
\n" ); document.write( " $\"Ng=Nb%2F4\"$
\n" ); document.write( " $\"Ng=60%2F4\"$
\n" ); document.write( " $\"highlight%28Ng=15%29\"$
\n" ); document.write( " \n" ); document.write( "

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