In three consecutive even integers, the product of the first and the third is 320. What is the middle even integer?

Correct answer: 18

Let the middle even integer be n. Since the integers are consecutive and even, the first and third are n − 2 and n + 2. Their product is (n − 2)(n + 2) = 320. Using the difference-of-squares identity gives n² − 4 = 320, so n² = 324. Thus n = 18 or n = −18. The options and the usual positive-integer interpretation select 18. Verification is immediate: the three integers are 16, 18, and 20, and the product of the first and third is 16 × 20 = 320. Option B is the first integer, option C is the third integer, and option D does not produce the stated product with its neighboring even integers.