The ratio of the present ages of a girl and her grandfather is 1 : 15 and that of her brother and grandfather is 3 : 15. After 2 years the ratio of the age of girl to that of her brother becomes 3 : 7. What is the present age of the grandfather?
1
55 years
2
60 years
3
66 years
4
Data inadequate
5
None of these