Answer:
27
Explanation:
If Fiona's age is x, Dan and Gavyn's ages respectively are x + 8 and x - 9. We can write:
x + x + 8 + x - 9 = 56
3x - 1 = 56
3x = 57
x = 19
The eldest is Dan (because x + 8 > x and x + 8 > x - 9). His age is x + 8 = 19 + 8 = 27.