Understand the logic:-
- Ram was married 10years ago .
- Then his father was alive and suppose they have 6+x members .
- Including his father its 6+x+1=x+7 members .
- A baby girl is born means 1 more people means x+8peoples
- His father expired means 1 people lost x+7people left.
- Which is same like previous .
- Its surely took atleast 1 year for borning of girl .
- Age of girl is Max 10-1=9years
The age of father must be 10(9)=90years
But there was 6 members more
so his fathers age should be 10(6)=60years.
