A man is 13 times as old as his son. In 10 years, he'll be 3 times as old. How old are they today?

Question

 I need to understand the equation and how to work it out. Thank you very much.

Answer 1

 

X is the son's age.

 

Man is 13X

 

3(X+10) = 13X + 10

 

3x + 30 = 13x + 10

 

0 = 13x + 10 - 3x - 30

 

0 = 10x - 20

 

20 = 10x

 

x = 20/10 = 2

 

Son is 2

Man is 26

 

IN 10 years, 12 vs. 36 which is 3 times as old.