Need help with integers

find the third of three consecutive odd integers such as that the sum of second and third is 48..

i know how to do the problem ..first we have to represent the three integers as:
first: n
second: n+2
third:n+4
but i dont know where the n+2 and n+4 came from

n+(n+2)+(n+4) the n+2 comes from the fact if we let n be odd then n+1 is even, and n+2 is odd. so if they are consecutive integers that are odd then we have n+(n+2)+(n+4). n+4+n+2=48 => n=21

21, 23, 25

n+6? xD