Posted by Anonymous on .
"Kim is 15. Kim's father is 39. In how many years will Kim's father be exactly twice as old as Kim will be?"

Mathematics 
Reiny,
let the number of years be x
x+39 = 2(15+x)
x+39 = 30 + 2x
9 = x
check:
in 9 yrs from now, kim will be 24 and Kim's dad will be 48 , which is twice Kim's age.