Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2021 — Part 09 Question 86

Math Olympiad Vault · MathNet 2021 — Part 09

Question 86

The six-digit number $20210A$ is prime for only one digit $A$. What is $A$?
  1. $1$
  2. $3$
  3. $5$
  4. $7$
  5. $9$