Skip to content / Đến nội dung
ThichHocToan.com

2017 AMC 10B Question 1

AMC10 · 2017 AMC 10B

Question 1

Mary thought of a positive two-digit number. She multiplied it by $3$ and added $11.$ Then she switched the digits of the result, obtaining a number between $71$ and $75,$ inclusive. What was Mary’s number?
  1. $11 $
  2. $12 $
  3. $13 $
  4. $14 $
  5. $15 $