document.write( "Question 327365: bob's father is 3 times old as bob. 4 years ago, he was 4 times older. how old is bob? \n" ); document.write( "
Algebra.Com's Answer #234491 by ganeshindia(11)\"\" \"About 
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Let the present age of bob be x years.
\n" ); document.write( "Let the present age of bob's father be y.
\n" ); document.write( "Therefore we get, y = 3x.( using the condition \"bob's father is 3 times as old as bob).
\n" ); document.write( "This gives 3x - y = 0 ..........(1)
\n" ); document.write( "Four years ago, \r
\n" ); document.write( "\n" ); document.write( "The age of bob = x - 4.
\n" ); document.write( "The age of bob's father = y - 4.\r
\n" ); document.write( "\n" ); document.write( "Therefore, we get , y - 4 = 4 ( x-4) (using the condition that four years ago he was four times older)
\n" ); document.write( "This gives y-4 = 4x - 16
\n" ); document.write( "4x - y = 12.........(2)\r
\n" ); document.write( "\n" ); document.write( "Solving the linear equations (1) and (2) we get
\n" ); document.write( "x = 12 and y=36.\r
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\n" ); document.write( "\n" ); document.write( "Sol:\r
\n" ); document.write( "\n" ); document.write( "Bob's present age x = 12 years
\n" ); document.write( "Father's present age y = 36 years
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