<PRE><B>Question 1019239</B>
Hi there,
a father is 27 years older than his son
F = 27 + S
Ten years from now the father will be 
twice as old as his son. 
F + 10 = 2(S + 10)
Replace F with (27 + S) from top equation.
27 + S + 10 = 2S + 20
Collect like terms
S - 2S = 20 - 27 - 10
-S = -17
S = 17
Son is 17 years old
Father is 44 years old
Hope this helps :-)</PRE>