There are five sheets of paper, each with a whole number printed on one side and an alphabet written on the other, as shown below.

What is the minimum number of sheets that you will turn over to determine if the statement stated below regarding them is true or false? What are the sheets you’ll be turning over?

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**Proposition:**

“

If one side of a sheet contains a prime integer, the other side contains a vowel.”

**Answer:**

Two Sheet 1 and Sheet 2

**Explanation:**

Sheet 1 must be turned over to verify the proposition’s truth. If the other side has no vowel, the proposition is false. This will confirm the statement.

Sheet 2 must also be flipped over. If it has a prime number on the other side, it will prove the statement false. This will use contradiction to prove that the statement is generally true in all instances.

Sheet 4 is not required to be turned over because the statement does not indicate that only sheets with a prime number on one side have a vowel on the other.

Sheets 3 and 5 are obviously useless for disproving or proving the proposition.