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MYTS 2019 — Grade 8 — Round 1 Question 11

MYTS · MYTS 2019 — Grade 8 — Round 1

Question 11

For a positive integer $n$, let $s(n)$ be its digit sum; for example $s(2019)=2+0+1+9=12$. How many three-digit numbers satisfy $s(n)>s(n+1)$?

Question illustration