The sum of six consecutive even numbers is 78. What is the sum of the squares of these numbers?
Let the first number be x x + x + 2 + x + 4 + x + 6 + x + 8 + x + 10 = 78 ⇒ 6 x + 30 = 78 ⇒ 6 x = 78 – 30 ⇒ 6 x = 48 ⇒ x = 8 Sum of the squares of the numbers = 8² + 10² + 12² + 14² + 16² + 18² = 1084