document.write( "Question 502124: Barry is 8 years older than his sister. In 3 years he will be twice as old as she will be then. How old is each now. \n" ); document.write( "
Algebra.Com's Answer #338821 by Maths68(1474)\"\" \"About 
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Let
\n" ); document.write( "Present age of Barry = b
\n" ); document.write( "Present age of sister = s
\n" ); document.write( "Barry is 8 years older than his sister means if we subtract 8 from present age of Barry both will be of equal age
\n" ); document.write( "s=b-8 ............(1)
\n" ); document.write( "In 3 years means we have to add 3 in their present age
\n" ); document.write( "s+3=b+3
\n" ); document.write( "then
\n" ); document.write( "he will be twice as old as
\n" ); document.write( "2(s+3)=(b+3
\n" ); document.write( "2s+6=b+3
\n" ); document.write( "2s=b+3-6
\n" ); document.write( "2s=b-3...............(2)
\n" ); document.write( "Put the value of s from (1) to (2), we have
\n" ); document.write( "2(b-8)=b-3
\n" ); document.write( "2b-16=b-3
\n" ); document.write( "2b-b=-3+16
\n" ); document.write( "b=13
\n" ); document.write( "Put the value of b in (1)
\n" ); document.write( "s=13-8
\n" ); document.write( "s=5
\n" ); document.write( "Present age of Barry = b = 13
\n" ); document.write( "Present age of sister = s = 5\r
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