Answer:
Let Craigs age = x
Therefore Dianes age = 25 + x ( since she's 25 years older)
Dianes + Craigs age = (25 + x) + x = 105 (They said both of their ages sums up to 105)
25 + 2x = 105
2x = 80
x = 40
Craigs age is 40 years old.
Dianes age is 65 years old.
