document.write( "Question 1089235: Three years ago the average age of a family of 5 members is 27 years. On the addition of a child to the family, the average age of the family is still 27 years. Find the present age of the child. \n" ); document.write( "

Algebra.Com's Answer #703586 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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Three years ago the average age of a family of 5 members is 27 years.
\n" ); document.write( " On the addition of a child to the family, the average age of the family is still 27 years.
\n" ); document.write( " Find the present age of the child.
\n" ); document.write( ":
\n" ); document.write( "let t = total of their ages 3 yrs ago
\n" ); document.write( " $\"t%2F5+=+27\"$
\n" ); document.write( "t = 5*27
\n" ); document.write( "t = 135
\n" ); document.write( "In 3 yrs, five people would add 15 yrs to the total; 150
\n" ); document.write( ":
\n" ); document.write( "let c = age of the child
\n" ); document.write( "we now have 6 people in the family
\n" ); document.write( " $\"%28%28150+%2B+c%29%29%2F6\"$ = 27
\n" ); document.write( "150 + c = 27 * 6
\n" ); document.write( "150 + c = 162
\n" ); document.write( "c = 162 - 150
\n" ); document.write( "c = 12 yrs is the age of the child \n" ); document.write( "

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