April 2001
$618,042.45.
Any college on the planet.
Each penny deposited to the son's account in the first month eventually causes a total of $1,964.17 in his account and $3,178.11 in the daughter's account.
Each penny deposited to the daughter's account in the first month eventually causes a total of $1,964.17 in her account and $1,213.94 in the son's account.
If the initial deposits are x cents and y cents, the daughter's wealth tells us that
3178.11x + 1964.17y + 7.50 = 1000000.00,
whose only solution (in positive integers) is x=73, y=391.
The son's wealth is then
1213.94*391 + 1964.17*73 + 7.50 = 618,042.45.
The monthly deposits are
3.91, 0.73, 4.64, 5.37, 10.01, 15.38, 25.39, 40.77, 66.16, 106.93, 173.09, 280.02, 453.11, 733.13, 1186.24, 1919.37, 3105.61, 5024.98, 8130.59, 13155.57, 21286.16, 34441.73, 55727.89, 90169.62, 145897.51, 236067.13, 381964.64, 618031.77.
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