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PIMSO 2025 - Mathematics - Senior Secondary - National Round Question 18

PIMSO Maths · PIMSO 2025 - Mathematics - Senior Secondary - National Round

Question 18

If $x\in\{1,2,3,\ldots,9\}$ and $f_n(x)=xxx\ldots x$ (n digits), then $f_n^2(3)+f_n(2)=$?
  1. $f_{2n}(1)$
  2. $-f_{2n}(4)$
  3. $2f_{2n}(1)$
  4. $f_n^2(1)$