# Mathcounts

##### Quoc Tran Anh Le Coodinator

05/08/2018 at 03:53##### Quoc Tran Anh Le Coodinator

05/08/2018 at 03:52-
Huy Toàn 8A (TL) 05/08/2018 at 13:38
Sum of odd-numbered digits ( - ) Sum of even-numbered digits or vice versa is divisible by 11

We have:

(2 + D + D) - (3 + 6 + 9) is divisible by 11

<=> 2 + 2D - 18 is divisible by 11

<=> 2D - 16 is divisible by 11

<=> 2 (D - 8) is divisible by 11

So Greatest common divisor (2 ; 11) = 1

=> D - 8 is divisible by 11

0 \(\le D\le9\)

=> D = 8

So The answer is : 386,892

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##### Quoc Tran Anh Le Coodinator

05/08/2018 at 03:51##### Quoc Tran Anh Le Coodinator

05/08/2018 at 03:50##### Quoc Tran Anh Le Coodinator

05/08/2018 at 03:50##### Quoc Tran Anh Le Coodinator

05/08/2018 at 03:49##### Quoc Tran Anh Le Coodinator

05/08/2018 at 03:49##### Quoc Tran Anh Le Coodinator

05/08/2018 at 03:48##### Quoc Tran Anh Le Coodinator

05/08/2018 at 03:47## 4727

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