<PRE><B>Question 320970</B>
A father is twice as old as his son. Ten years ago he was three times as old as his son.
:
a) If the son is x years old, determine the age of the father in terms of x.
f = 2x
:
b) Find the ages of the father and son ten years ago in terms of x.
f - 10 = 3(x - 10)
f - 10 = 3x - 30
f = 3x - 30 + 10
f = 3x - 20; father in terms of x, 10 years ago
:
c) What are their present ages.
replace f with 2x in the above equation
2x = 3x - 20
20 = 3x - 2x
20 = x
son is 20, then father is 40</PRE>