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# number theory marathon

lets start a number theory marathon..... QUESTION 1- N is a 50-digit number (in decimal representation). All digits except the 26th digit (from the left) are 1. If N is divisible by 13, find its 26-th digit.

Note by Superman Son
4 years, 1 month ago

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Hint: Note that $$111111 \equiv 0 \pmod{13}$$

As such, the $$26$$th digit will be $$3$$ · 4 years ago

now u give a question · 4 years ago

Sure.

Try this. · 4 years ago

$$111111 \equiv 0 \pmod{13}$$ so the 26th digit is 3 · 4 years ago

I have seen this question before..... · 4 years ago