Answer:
Step-by-step explanation:
Let Alex's age = x
Mark's age = y
Luke's age = a
x + y + z = 12
The possible combinations for their age are
1. 6, 3, 3
2. 3, 3, 6
3. 4,4, 4
4, 2, 2, 8
5. 8, 2, 2
6. 2, 8, 2
7. 9, 2, 1
Etc the age can keep going as long as you can find any three numbers and add them to give you 12
$391
