The average of 5 consecutive numbers is 50, then difference between “product of largest and smallest number” with “product of fourth and second number” is: A. 3 B. - 6 C. 0 D. 10

The numbers are 48, 49, 50, 51 and 52 (average 50). Largest × smallest = 52 × 48 = 2496 and fourth × second = 51 × 49 = 2499. The difference between the two products is 3 (in general (n² − 4) and (n² − 1) differ by 3).