Solution

The correct answer is {1, 4}

SOLUTION:

X= {1 ≤ n ≤ 8} So, X = {1, 2, 3, 4, 5, 6, 7, 8}

P= "n is an even integers" So, P = {2, 4, 6, 8}

Q = "(3 ≤ n ≤ 7) ^ (n ≠ 6)" So, Q = {3, 4, 5, 7}

P ↔ Q = (¬P v Q)  ^ (P v ¬Q)

P ↔ Q = ({1, 3, 5, 7} v {{3, 4, 5, 7}) ^ ({2, 4, 6, 8} v {1, 2, 6, 8})

P ↔ Q = {1,3, 4, 5, 7} ^ {1, 2, 4, 6, 8}

P ↔ Q = {1, 4}

So, Correct answer is Option 1 {1, 4}