In the three digits composed of 1, 2, 3, 4 and 5, the sum of all digits is odd A. 36 B. 24 C. 18 D. 6

In the three digits composed of 1, 2, 3, 4 and 5, the sum of all digits is odd A. 36 B. 24 C. 18 D. 6

According to the principle of classification and counting, there are 18 + 6 = 24. So choose B

How many natural numbers can be formed by numbers 0,1,2,3,4,5 without repetition

5 * 5 * 4 * 3 * 2 * 1 = 600

What is the number of non repeating and natural numbers that can be made up of 1, 2, 3 and 4?

There are four kinds of natural numbers composed of 1, 2, 3 and 4 that do not repeat numbers: (x0d1) there are four natural numbers with one digit that do not repeat numbers: 1, 2, 3 and 4 respectively; (x0d2) there are 12 natural numbers with two digits that do not repeat numbers: there are four choices for ten digits and three choices for single digits, Therefore, there are 4 * 3 = 12 for two digit numbers that do not repeat, 24 for three digit natural numbers that do not repeat, 24 for four digit natural numbers that do not repeat, and 24 for four digit natural numbers that do not repeat

How many natural numbers can be made up of the four numbers 1.2.3.4?

One number: Four
2 numbers: 4 × 3 = 12
3 numbers: 4 × 3 × 2 = 24
4 numbers: 4 × 3 × 2 × 1 = 24
It can be composed of 64 natural numbers without repeating numbers

How many natural numbers less than 2000 without repeated numbers can be formed by numbers 0, 1, 2, 3 and 4

Single digit: 5
Tens: 4 × 4 = 16
Hundreds: 4 × 4 × 3 = 48
Thousand digits: 2 × 4 × 3 × 2 = 48
5+16+48+48=117
Please choose a satisfactory answer, thank you

How many natural numbers larger than 3000 without repeated numbers can be formed with 0 1 2 3 4 5?

Six digits: a (6,6) / 6 * 5 = 600
Five digit: a (6,5) / 6 * 5 = 600
Four digits: a (6,4) / 2 = 180
There are 1380 species in 600 + 600 + 180

How many four digit numbers can be formed by taking any two numbers from 1, 3 and 5 and any two numbers from 0, 2 and 4? How many even numbers are there?

There are three ways to take two numbers from 1,3,5. Suppose that 0 is not taken, and there are two ways to take. At this time, four digits C (2,3) * a (4,4) = 3 * (4 * 3 * 2 * 1) = 72C (2,3): choose two numbers from 1,3,5, and a (4,4): arrange four numbers completely. Suppose that 0 is taken, there are two ways to take C (2,3) * C (1,2) * C (1,3) * a (3,3) = 3 *

How many even four digit numbers can be made up of numbers 0, 1, 2, 3 and 4

The numbers 0, 1, 2, 3 and 4 can be used to form 2 × 3 × 3 × 2 + 1 × 4 × 3 × 2 = 60 even numbers without repetition

Take any two numbers from 1,3,5,7,9 and any two numbers from 0,2,4,6,8 to form a four digit number without repetition
(1) How many can be divided by 5?
(2) How many odd numbers are not adjacent?
(3) How many are bigger than 7690?

(1) The four digits that can be divided by 5 can only be 5 or 0-1. Let 0c52 * C41 * A33 be two, let 5c41 * C52 * a33c52 * C41 * A33 + C41 * C52 * A33 = 10 * 4 * 6 + 4 * 10 * 6 = 480 (2) in the four numbers, 2 odd 2 even one, even start C41 * C51 * C41 * C41 = 4 * 5 * 4 * 4 = 320 two, odd start C51 * C51 * C4

How many five digit numbers can be formed by taking any three numbers from 1, 3, 5, 7 and 9 and any two numbers from 2, 4, 6 and 8?

There are C35 methods to take any three numbers from 1, 3, 5, 7 and 9, and C24 methods to take any two numbers from 2, 4, 6 and 8. Then the five numbers are arranged in full, with a total of c35c · 24 · A55 = 7200, so a total of 7200 five digit numbers without repetition can be formed