How many non repeating numbers can nine numbers make up three digits?

The original question should be like this: how many non repeating three digit numbers can be made up of 1-9 9 numbers? There are 9 ways to select a hundred digit from 9 numbers; if a 100 digit number is selected, it can't be selected again because it can't be repeated, and only one of the remaining 8 digits can be selected from 10 digit

What is the sum of all these five digits, which is made up of five digits without repetition?

Without repetition, there are 120 five digits (5 * 4 * 3 * 2 * 1)
Among them, all of you appeared 24 times in 1357 9, so the total is
（24*1+24*3+24*5+24*7+24*9)(10000+1000+100+10+1)=24*25*11111=6666600

By the numbers 0,1,2 The 10 digits make up the five digit number without repetition How many odd numbers are more than 50000

When the first digit is 5, 7, 8, 9, it must be one of 5, 6, 7, 8, 9. When the first digit is 5, 7, 9, because it is an odd number, the end must be removed from the first odd number, and the remaining 4 odd numbers can be selected

How many five digit numbers without repeating numbers can be made up of numbers 1-9?

Permutation combination, 5 out of 9 permutations, 9x8x7x6x5

How many non repeating five digits can be made up of 678 905 digits?

4 × 4 × 3 × 2 × 1 = 96

Take any two odd numbers and two even numbers from the seven numbers 1, 2, 3, 4, 5, 6, and 7 to form a four digit number without repeating numbers, in which the odd number is () A. 432 B. 288 C. 216 D. 108

∵ from the meaning of the question, the problem is a step-by-step counting principle,
The first step is to take 2 out of 4 odd numbers, and then 2 out of 3 even numbers. There are 18 kinds of c42c32,
The second step is to arrange 4 numbers, of which a21a33 = 12,
The number of odd numbers is 18 × 12 = 216
Therefore, C

Take any two odd numbers and two even numbers from the six numbers of 0, 1, 2, 3, 4, 5 to form the number of four digits without repeating numbers______ (answer with numbers)

Take two odd and two even numbers from six numbers,
When the even number does not contain 0, there is c22c32a44 = 72,
When even number contains 0, c21c32c31a33 = 108,
The number of four digit numbers without repeating numbers is 72 + 108 = 180,
So the answer is: 180

What is the number of 4-digit odd numbers without repeating numbers, which is composed of two odd numbers and two even numbers from 0,1,2,3,4,5?

There are three even numbers of 0, 2 and 4, and there are three methods to take C (3,2) = 3
1. 3, 5 three odd numbers, C (3,2) = 3
Take the four numbers and arrange them
If it is an odd number, then there are three ways to get a bit C (3,1) = 3, and a thousand bit cannot be 0. Except for 0 and selecting an odd number as a bit, there are 4 methods for taking C (4,1) = 4, and a (4,2) = 12 for the other two bits
So there are:
3x4x12 = 144 methods
That is to say, the number of odd numbers is 144

Use 0, 1, 2, 3, 4 to form a five digit number without repeating numbers, and there is an even number between two odd numbers, such as () A. 12 B. 28 C. 36 D. 48

There are three even numbers and two odd numbers in 0, 1, 2, 3 and 4
① If 0 is sandwiched in the middle by odd numbers, the order of odd numbers 1 and 3 should be considered first, and then 1, 0 and 3 should be regarded as a whole and arranged with 2 and 4. There are 6 cases of A33 = 6; therefore, when 0 is sandwiched in the middle by odd numbers, there are 2 × 6 = 12 cases;
② If 2 is sandwiched in the middle by odd numbers, the order of odd numbers 1 and 3 is considered first, and then 1, 0 and 3 are regarded as a whole and arranged with 2 and 4. There are 6 cases of A33 = 6, of which 0 is in the first place in 2 cases, and there are 6-2 = 4 arrangements;
Therefore, when 2 is sandwiched in the middle by odd numbers, there are 2 × 4 = 8 cases;
③ When 4 is sandwiched in the middle by an odd number, there are 8 cases in which 2 is sandwiched in the middle by an odd number,
There are 12 + 8 + 8 = 28 kinds of such five digits;

Take three even and four odd numbers out of the nine numbers from 1 to 9 ① How many seven digits can you make up without repeating numbers? ② How many of these seven digits are even three? ③ How many even numbers and odd numbers are arranged together among the seven digits in ①? ④ How many seven digits are any two randomly not adjacent?

① Step by step: the first step is to take 3 out of 4 even numbers, which can have C43 cases;
The second step is to take 4 out of 5 odd numbers, but there are some cases in C54;
The third step is to arrange 3 even numbers and 4 odd numbers, which can have a77 cases,
Therefore, the number of seven digits in accordance with the meaning of the title is c43c54a77 = 100800;
② Among the seven digits mentioned above, three even numbers are arranged together in A33 cases,
Therefore, three even numbers are arranged together in the case of c43c54a55a33 = 14400;
③ Among the seven digits mentioned above, there are A33 cases for 3 even numbers and a44 cases for 4 odd numbers,
There are 5760 c43c54a33a44a22
④ In the above seven digits, even numbers are not adjacent, so four odd numbers can be arranged first,
Insert three even numbers into five neutral positions respectively, and there are altogether 28800 c54a44c43a53

How many non repeating numbers can nine numbers make up three digits?