The answer is 37 years old.
I = -425x² + 45500x -650000
I = 450000
-425x² + 45500x -650000 = 450000
-425x² + 45500x - 650000 - 450000 = 0
-425x² + 45500x - 1100000 = 0
Divide all factors by 25:
- 17x² + 1820x - 44000 = 0
This is quadratic equation (ax² + bx + c = 0)

Since, the youngest age is needed, the correct answer is x = 37