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VTMO 2015 — Grade 2 — semifinal Question 18

VTMO · VTMO 2015 — Grade 2 — semifinal

Question 18

Write $1 \text{--} 20$ consecutively as $123456 \ldots 181920$. How many digits are written?
  1. $20$
  2. $22$
  3. $29$
  4. $30$
  5. $31$