document.write( "Question 789602: Sister is 10 yrs older thn brother , after 3 yrs sister is twice thn brother so what r the ages of both..........??? \n" ); document.write( "

Algebra.Com's Answer #478952 by KMST(5328) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"b\"$ = age of the brother, in years, at the start of the 3 years
\n" ); document.write( " $\"b%2B10\"$ = age of the sister, in years, at the start of the 3 years
\n" ); document.write( " $\"b%2B3\"$ = age of the brother, in years, after 3 years
\n" ); document.write( " $\"b%2B10%2B3=b%2B13\"$ = age of the sister, in years, after 3 years
\n" ); document.write( "
\n" ); document.write( "If after 3 years the sister is twice as old as the brother,
\n" ); document.write( " $\"b%2B13=2%28b%2B3%29\"$
\n" ); document.write( "Then, solving step by step:
\n" ); document.write( " $\"b%2B13=2%28b%2B3%29\"$ --> $\"b%2B13=2b%2B2%2A3%29\"$ --> $\"b%2B13=2b%2B6%29\"$ --> $\"b%2B13-6=2b%29\"$ --> $\"b%2B7=2b%29\"$ --> $\"7=2b-b%29\"$ --> $\"highlight%28b=7%29\"$
\n" ); document.write( "That means:
\n" ); document.write( " $\"b%2B10=7%2B10=highlight%2817%29\"$ = age of the sister, in years, at the start of the 3 years
\n" ); document.write( " $\"b%2B3=7%2B3=10\"$ = age of the brother, in years, after 3 years
\n" ); document.write( " $\"b%2B13=7%2B13=20\"$ = age of the sister, in years, after 3 years
\n" ); document.write( "At the start the brother is 7 years old, and the sister is 17.
\n" ); document.write( "After 3 years, the brother is 10, and the sister is 20.
\n" ); document.write( " \n" ); document.write( "

\n" );