https://www.youtube.com/watch?v=1lHDCAIsyb8
https://mindyourdecisions.com/blog/2017 … ay-puzzle/
Welcome to the forum. Any restrictions on the number of digits? For instance, n = 0 works. Two digits can be ruled out by letting n = 10a + b (which has no solutions as per your constraints), and three digits can also be ruled out the same way via modulo arithmetic. If a non-trivial solution exists, it may be large.
EDIT: I have a solution, but it is 21 digits long. I don't know if this is the smallest such solution (and, if this was intended to be a quick brain teaser, it seems unlikely to be). I'll post up a rough solution tomorrow.
]]>Find a number n that, when you swap the first and last digits, it becomes 2n. Please, try to find it in decimal system.
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