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In your sequence, count the number of members "N".
Of them, count the number of even numbers "n".
The probability under the question is the ratio P = .
Strictly speaking, in your post, there is a moment that makes it nonsensical.
From the post, it is unclear, how the first number line is connected with the rest of the text.
Also, it is not clear why the digits are separated into groups and what every group means.
In Math, it is NOT ACCEPTABLE to formulate and to present problems in this way.