document.write( "Question 518922: In five years time,a father will be three times as old as his son.Four years ago the father was six times as old as his son.Find their present ages? \n" ); document.write( "
Algebra.Com's Answer #345291 by Maths68(1474)\"\" \"About 
You can put this solution on YOUR website!
Let
\n" ); document.write( "Present age of father = f
\n" ); document.write( "Present age of son = s\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "In five years time,
\n" ); document.write( "Man age = f+5
\n" ); document.write( "Son age = s+5
\n" ); document.write( "then father will be three times as old as his son.
\n" ); document.write( "f+5=3(s+5)
\n" ); document.write( "f+5=3s+15
\n" ); document.write( "f=3s+15-5
\n" ); document.write( "f=3s+10..........(1)\r
\n" ); document.write( "\n" ); document.write( "Four years ago
\n" ); document.write( "Man age = f-4
\n" ); document.write( "Son age = s-4
\n" ); document.write( "then father was six times as old as his son.
\n" ); document.write( "f-4=6(s-4)
\n" ); document.write( "f-4=6s-24
\n" ); document.write( "f=6s-24+4
\n" ); document.write( "f=6s-20..........(2)
\n" ); document.write( "Put the value of f from (1) to (2)
\n" ); document.write( "3s+10=6s-20
\n" ); document.write( "3s-6s=-10-20
\n" ); document.write( "-3s=-30
\n" ); document.write( "-3s/-3=-30/-3
\n" ); document.write( "s=10
\n" ); document.write( "Put the value of s in (1)
\n" ); document.write( "f=3(10)+10
\n" ); document.write( "f=30+10
\n" ); document.write( "f=40\r
\n" ); document.write( "\n" ); document.write( "Present age of father = f = 40 years old
\n" ); document.write( "Present age of son = s = 10 years old
\n" ); document.write( " \n" ); document.write( "
\n" );