Answer: 11
Explanation:
So, together they are 23. This means we need all three of their ages to add up to 23.
Honestly, I just would just start guessing multiples of low numbers to try to find Gabriel's and Alexis's ages first.
So...
Alexis being 1 is definitely way too low.
2 is also pretty low.
But 3? That might just work.
So if Alexis is 3, this means that Gabriel is 9. This would then mean that Karine is 11.
11+9+3=23.
It seems to work.
Alexis - 3
Gabriel - 9
Karine - 11