The sum of present ages of a mother and daughter is 99 years. When the mother was as old as the present age of daughter is now, her age was 4 times to the age of her daughter at that time. The ratio of present age of mother and daughter is?

7 : 4

                Mother  :   Daughter

Present:      x        :        y

Before*       y        :      2y - x 

*(when mother was as old as her daughter is now)  

Now, ATQ,

⇒ y = 4 ( 2y - x )

⇒ 4x = 7y

⇒ x :  y = 7 :  4