Answer:
Sydney is 28
Explanation:
Let's call Daisy D, and call Sydney S.
Daisy is 10 years older.
So D = S + 10
S = D - 10
Sum of their ages = 66.
D + S = 66
D + (D - 10) = 66
2D - 10 = 66
2D = 76
D = 38
If Daisy is 10 years older, Sydney must be 38 - 10 = 28.
to check if we're correct, 38 + 28 = 66.