document.write( "Question 988467: The total age of family of 4is 68 4 years ago it was 53 how old is the youngest \n" ); document.write( "
Algebra.Com's Answer #609086 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Maybe we should use some algebra in there somewhere instead\r\n" );
document.write( "of using trial and error.\r\n" );
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document.write( "Normally we would expect that if the sum of the 4 people's\r\n" );
document.write( "ages is now 68, then four years ago each would have been 4 \r\n" );
document.write( "years younger, and the sum would have been 4*4 or 16 less.\r\n" );
document.write( "But 16 less than 68 is 52, not 53. \r\n" );
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document.write( "So the youngest child must not have been born 4 years ago.\r\n" );
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document.write( "So 4 years ago there were only 3 members of the family\r\n" );
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document.write( "Let the sum of the ages of the 3 older members of the family be x.\r\n" );
document.write( "Let the age of the youngest child who wasn't born 4 years ago be y.\r\n" );
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document.write( "Then x + y = 68 and since 4 years ago there were only 3 members of\r\n" );
document.write( "the family the sum would have been only 4*3 or 12 less. So\r\n" );
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document.write( "x-12 = 53\r\n" );
document.write( "x = 65\r\n" );
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document.write( "And since x + y = 68, substituting x = 65\r\n" );
document.write( "         65 + y = 68\r\n" );
document.write( "              y = 3\r\n" );
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document.write( "The youngest child is 3.\r\n" );
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document.write( "Edwin

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