Problema Solution

I need the process to solve this problem:

Bob is one third the age of his father. In 12 years he will half the age of his father. How old is each now??/

Answer provided by our tutors

bob's father's age= 3x

bob's age= x

 

In 12 years,

Bob's father's age= 2(12 + x)

Bob's age= 12 + x

 

3x + 12 = 2(12 + x)

3x + 12 =24 + 2x

x =12

 

Bob's age= 12

Father's age= 36