Vòng 3 - Vòng chung khảo

1-10645

2-10

3-1

4-83.75%

5-47%-53%

6-not result 

7-Because the first 2 numbers are the same, we will omit it to make the problem simpler, because if we say 1 of 2 numbers in thousands and hundreds, it will not be possible to solve the password.
Suppose Anh tells Minh the number is in the tens, Binh is in the units because the roles of the two of you in the problem are the same.
We divide it into 2 parts:
+) General unit:
- 19
- 34, 24
- 38, 18
- 06, 26
- 07
- 05, 35
+) General tens:
- 05, 06, 07
- 19, 18
- 24, 26
- 34, 38, 35
We see that after dividing in the units line, the numbers 19 and 07 stand odd
If Anh says 1 or 0 to Minh then both of you will know the answer,
And Binh said he didn't know but Minh certainly didn't know
⇒ I can't tell Minh the number 1 or 0
⇒ type 05, 06, 07, 19, 18
We can also eliminate 24 and 34 because the number 4 is repeated 2 times in the unit row as understood in the first sentence of Binh as above.
That leaves only 26, 38 and 35 . left
Because you both know the answer then
+) If your friend Anh tells you Minh number 3, then 2 you can't have the answer because there are 2 numbers 38 and 35 left.
⇒ The correct answer should be 26 or 1126 is the password of the lock