Question 575258
Dana is 20 years older than daughter Kim.  Ten years ago, Dana was twice as old as Kim was then.  How old are Dana and Kim now?
sol:
let daughter age = x ,dana age = 20 + x
given :Ten years ago, Dana was twice as old as kim
(20 + x) - 10 = 2*(x - 10)
solving for x you get kim = 30 yrs & dana = 50 yrs.