Question 1
10 years ago, the ratio of Alex's age to Lars's age was 1:3. 20 years from now, the ratio will be 2:5. Find Alex's present age.
Let Alex's present age = x, Lars's present age = y
10 years ago: (x-10)/(y-10) = 1/3
20 years from now: (x+20)/(y+20) = 2/5
Solving these equations gives x = 20, y = 60
10 years ago: (x-10)/(y-10) = 1/3
20 years from now: (x+20)/(y+20) = 2/5
Solving these equations gives x = 20, y = 60