Six consecutive whole numbers are given. The sum of the first three numbers is 27. What is the sum of the last three numbers?

Question: Six consecutive whole numbers are given. The sum of the first three numbers is 27. What is the sum of the last three numbers?

Solution:
let the numbers be x - 2, x - 1, x, x + 1, x + 2, x + 3

x - 2 + x - 1 + x = 27
⇒ 3x - 3 = 27
⇒ 3x = 27 + 3 = 30
⇒ x = 30/3
∴ x = 10

the sum of the last three numbers is = x + 1 + x + 2 + x + 3
= 10 + 1 + 10 + 2 + 10 + 3
= 36