Use 1, 2 and 3 to form a four digit number. If each number appears at least once, then the probability that such four digit number can be divided by 3

The characteristic of a number divisible by 3 is that the sum of each digit is a multiple of 3
1. 2 and 3 make up 4 digits. Each digit appears at least once, so one of them has to appear twice. 1 + 2 + 3 = 6 is a multiple of 3, so only 3 appears twice can it be divided by 3
So the probability is one in three

The number on each digit of a five digit number is just a continuous non-zero natural number. Can this number be divided by 9?

No
Let the five digit numbers be a, a + 1, a + 2, a + 3 and a + 4
Number sum x = 5A + 10
Numbers are just continuous non-zero natural numbers
So, the value of a is
1≤a≤5
A = 1 x = 15 divisible by 3
a=2 x=20
a=3 x=25
A = 4 x = 30 divisible by 3
a=5 x=35
Only when a = 1 and a = 4 can the number be divided by 3
Then, the corresponding numbers are
12345 ,54321,45678 ,87654
These four numbers are not divisible by 9!
Therefore, the number in the title can not be divided by 9!

The largest number composed of 0, 1, 2, 3, 4 and 6 divisible by 11 and 2

The difference between the sum of the odd and even digits of an integer is a multiple of 11
Therefore, the sum of odd digits is equal to the sum of even digits (that is, 0 times of 11) and 0 + 2 + 6 = 1 + 3 + 4 is selected
In order to do that, there are six digits in total, and the maximum number is required, so 6 is in the first place, and 6, 2 and 0 are even digits, and 1, 3 and 4 are odd digits
It is also required to be divisible by 2, so the end number is 0, 2, 4, 6 and 8, and each bit is odd, and only 4 satisfies the condition at the same time
In other places, there are 632104 from big to small

Use 1, 2 and 3 to form a four digit number. If each number appears at least once, then the probability that such four digit number can be divided by 3