Jack is 3 times a as old as lacy. 8 years ago the sum of their ages was 25. how old are they now?

Let x = age of jack

Let y = age of Lacy

x=3y (Jack age is 3 times that of Lacy)

(x+y)-8 = 25

Substituting value of x:

(3y+y) -8 = 25

4y - 8 = 25

4y = 33

y = 33/4 = 8.25 or 8 years 3 months (age of Lacy)

x = 3(8.25) = 24.75 or 24 years 9 months (age of Jack)

Checking:

Substituting in equation ( x + y ) -8 = 25

24.75 + 8.25 - 8 = 25

25 = 25