In 2005 Cora was three times as old as her son Jason ,Four years beck then,she was four times as old as Jason.In what year Jason born?

Sagot :

Let x be Jason's age in 2005
     3x be Cora's age in 2005

Four years back,
Cora's age = 3x-4
Jason's age = x-4

Cora was four times as old as Jason four years ago:
3x-4 = 4(x-4)

Solve for x:
3x-4 = 4x-16
16-4 = 4x-3x
   12 = x

Jason's age in 2005 is 12.  Therefore, Jason was born in  1993.