Question 1032009
sister is x years
boy is 2x
father is 4x
x+50=8x, twice as old as her father is now (I have to assume that).
7x=50
x=(50/7)
boy is 100/7 years old (14 2/7) years
father is 200/7 years old (28 4/7)
in 50 years, the 7 (1/7) year old girl will be 57 (1/7) years, and that is twice as much as her 28 (4/7) year old father, who has a son 14 2/7 year old.