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?

**Answer Choices**

A. 11

B. 12

C. 13

D. 14

E. 15

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?

**Answer Choices**

A. 11

B. 12

C. 13

D. 14

E. 15