Solution to the Problem:
The third child would get $3,456.
The second child gets 20% more than the oldest child (who got $3,600).
So, the second child got $3,600 plus 20% of $3,600, for a total of $4,320.
Since the second child gets 25% more than the youngest child,
4320 = 1.25 x, where x is the amount that the youngest gets.
Solving the equation, x = 3456.