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These seven numbers are arranged in a column Two numbers must be next to each other, requiring that the two numbers cannot be adjacent to each other then there can be no 123 or 321 There are a total of 2 * 6 * 5 * 4 * 3 * 2 ways to remove 123 321 case.

2*5*4*3*2 results are 1200 methods.

These seven numbers are arranged in a column, and the two numbers must be next to each other, and they must be seen as a whole, and 34 or 43 have 2*6*5*4*3*2 methods, and the adjacent methods are removed, and a whole, 12 or 21

2*2*5*4*3*2 Subtract the two 960 ways.

The train of thought is definitely right, but it's too sleepy, and the mind is a little unclear, so let's think about it carefully.

1) 2 and 3 as a number, then this group of numbers is arranged as 1 * 2 * 3 * 4 * 5 * 6 = 720, and 2 and 3 may be 23 or 32, then the arrangement of this number is 720 * 2 = 1400, the arrangement of the following four digits and 123 five numbers is 1 * 2 * 3 * 4 * 5 = 120, the next four digits and 321 five numbers are also 120 kinds, then the arrangement of these seven numbers is 1400-240 = 1160 kinds of arrangement.

Treat 3 and 4 as a number, then the arrangement of this group of numbers is 1*2*3*4*5*6=720, and 3 and 4 may be 34 or 43, then the arrangement of this number is 720*2=1400, minus 12 or 21 and the arrangement of the following or The four permutations of these five numbers may be: 1*2*3*4*5*4=480, then the arrangement of these seven numbers is 1400-480=920 kinds of arrangement.

1. You can see a number. Let's assume that it is 23, so that the arrangement of the 124567 has a total of 6*5*4*3*2=720, which, 1 can not be in front of 2, and it is regarded as a number with a total of 5*4*3*2=120, then there is a total of 720-120=600, and vice versa, a total of 600*2=1200 kinds.

2, this should be more than the above minus a 120 so it should be, 720-120 * 2 = 480, so a total of 480 * 2 = 960

These seven numbers are arranged in a column, and the two numbers must be next to each other, and they must be regarded as a whole, and two cases should be taken into account, there are 2 * 6 * 5 * 4 * 3 * 2 * 1 = 1440 methods; In addition, there are 2*5*4*3*2*1=240 ways to treat not adjacent, to see that as a whole, and to exclude . Finally, 1440-240=1200 methods are found.

2) Treat as a whole, and take into account the two cases, there are 2*6*5*4*3*2*1=1440 methods; In addition, 12 is not adjacent, and considering the four cases of 43, there are 4*5*4*3*2*1=480 methods; So in the end there are 1440-480 = 960 methods.

After depreciation, the latest ** of painting tools has dropped by 5 cents. The total price of the 19 parts of the painting tool after depreciation is 6 pieces less than that of the 18 before depreciation. Q: Before depreciation?

19y+6=18x

19x-19y=

I don't know if it's right.