document.write( "Question 704491: The oldest child in a family of four children is three times as old as the yougest. The two middle children are 10 and 17 years old. If the average age of the children is 11.75, how old is the youngest child? \n" ); document.write( "

Algebra.Com's Answer #434167 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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The oldest child in a family of four children is three times as old as the youngest.
\n" ); document.write( "let a = the age of the youngest
\n" ); document.write( "then
\n" ); document.write( "3a = the age of the oldest
\n" ); document.write( ":
\n" ); document.write( "The two middle children are 10 and 17 years old.
\n" ); document.write( " If the average age of the children is 11.75, how old is the youngest child?
\n" ); document.write( " $\"%283a+%2B+17+%2B+10+%2B+a%29%2F4\"$ = 11.75
\n" ); document.write( "multiply both sides by 4 and combine like terms
\n" ); document.write( "4a + 27 = 4(11.75)
\n" ); document.write( "4a = 47 - 27
\n" ); document.write( "4a = 20
\n" ); document.write( "a = 20/4
\n" ); document.write( "a = 5 yrs old is the youngest
\n" ); document.write( ";
\n" ); document.write( "You can check this in the original equation
\n" ); document.write( "(15 + 17 + 10 + 5)/4 \n" ); document.write( "

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