Author Topic: Long digits  (Read 5213 times)

MrPuzzle

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Long digits
« on: 九月 03, 2004, 08:41:39 am »
Let A be the sum of the decimal digits of 4444^4444, and B be the sum of the decimal digits of A. Find the sum of the decimal digits of B.

sean

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7
« Reply #1 on: 九月 03, 2004, 03:33:15 pm »
A< 9(4444*4+1)<9*10^5,
B<9*6=54
C<14.

4444^4444=7 mod 9