PASCAL 2020 Problem 19

Each of the following 15 cards has a letter on one side and a positive integer on the other side.

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What is the minimum number of cards that need to be turned over to check if the following statement is true?

“If a card has a lower case letter on one side, then it has an odd integer on the other side.”

Answer Choices
A. 11
B. 9
C. 7
D. 5
E. 3