List the first five positive even integers?

2 4 6 8 10

Answer: 30

Analysis:

0 is an integer, but not a positive integer. In fact 0 is neither positive nor negative. The smallest positive integer is 1. Since the even integers are given by the formula 2n where n = 1, 2, 3, 4, 5, ..., the first 5 even positive integers are

2, 4, 6, 8, 10

and their sum = 2+4+6+8+10 = 30 (You can also use the formula n (n+1) to get the same sum by substituting n = 5).