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Permutation and combination: take any three of the six numbers 1, 2, 3, 4, 5, 6 to form 3-digit even numbers which can not be repeated?
A total of 3x5x4 = 60 species
How many (1) four even numbers (2) with no repeating numbers between 3000 and 8000 can be four odd numbers at the positive position of 5
one point one two eight eight
two point two two four
Permutation and combination: the 6 numbers of 0 ~ 5 can be used to form 4 digits without repetition. How many even numbers are there? How many odd numbers? The six numbers from 0 to 5 can be used to make up a non repetitive one (1) How many 4-bit even numbers? How many odd numbers? (2) How many four digits are divisible by 5? (3) How many four digits are divisible by three? (4) How many four digits are divisible by 15? (5) How many three digits are ten more than one? (6) How many numbers larger than 240135 can be formed? If the six digits are arranged from small to large, what number is 240135?
(1) Considering that 4-digit is ABCD, a ≠ 0, when d = 0,2,4d = 0, C has 5 choices, B has 4, a has 3, 5 * 4 * 3 = 60, d = 2,4, a has 4, B has 4, C has 3, and 2 * 4 * 4 * 3 = 96 4-digit even number has 60 + 96 = 156 ∵ 4-digit only needs a ≠ 0,
Use 1,2,3,4 number cards each, take two cards each time to form a two digit number, which can form () even numbers A. 6 B. 7 C. 8 D. 9
Two even numbers composed of 1, 2, 3 and 4 are as follows:
12，14，24，32，34，42；
There are six in all
Therefore, a
Use 1,2,3,4 number cards each, take two cards each time to form a two digit number, which can form () even numbers A. 6 B. 7 C. 8 D. 9
Two even numbers composed of 1, 2, 3 and 4 are as follows:
12，14，24，32，34，42；
There are six in all
Therefore, a
Use 1,2,3,4 number cards each, take two cards each time to form a two digit number, which can form () even numbers A. 6 B. 7 C. 8 D. 9
Two even numbers composed of 1, 2, 3 and 4 are as follows:
12，14，24，32，34，42；
There are six in all
Therefore, a
With three, four, five four number cards, take two at a time to form a two digit, can form () even number
Three, multiplication principle!
They are 34, 44, 54
Use 3,4,5 four digital cards, take two at a time to form a two digit, can form (3) even number
The top ten can be: 3, 4, 5,
There are three options,
There's one in each, four
1 choice,
There are three
Use 1,2,3,4 number cards each, take two cards each time to form a two digit number, which can form () even numbers A. 6 B. 7 C. 8 D. 9
Two even numbers composed of 1, 2, 3 and 4 are as follows:
12，14，24，32，34，42；
There are six in all
Therefore, a
How many different three digit numbers can be made up of 0, 1, 2, 3 and 5? How many even numbers, how many multiples of 5, and how many multiples of 3?
The number of three digits: 4 × 4 × 3 = 48
Even number: 4 × 3 + 3 × 3 = 21
Multiple of 5: 4 × 3 + 3 × 3 = 21
Multiple of 3: use (0, 1, 2), (0, 1, 5), (1, 2, 3), (1, 3, 5)
So there are: 4 + 4 + 6 + 6 = 20
Take three pieces from the following four numbers and form three digits as required. 5013 odd even 2 multiple 5 multiple 3 is both a multiple of 2 and 3 5 0 1 3 Odd number even numbers Multiple of 2 Multiple of 5 It is a multiple of 3 and a multiple of 2: Hurry up! It's urgent
Odd number 5013 5031 5103 5301 1053 1035 1503 1305 3105 3501 3015 3051
Even 5130 5310 1530 1350 3150 3510
2 times 5130 5310 1530 1350 3150 3510
5 times 5130 5310 1035 1530 1350 1305 3150 3105 3510 3015
3,2 times 5130 5310 1530 1350 3150 3510
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