Dan is 8 years older than Fiona. Gavyn is 9 years younger than Fiona. If the total of their ages is 56, how old is the eldest of them?

27

Step-by-step 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.