Answer:
The Number of unique permutation is 6,615
Explanation:
This particular permutation deals with words that have repeated letters.
Given word = "ONGOING"
the formula for the permutation is

where n is the amount of letters in the word, and m A , m B , ... , m Z are the occurrences of repeated letters in the word. Each m equals the amount of times the letter appears in the word.
So in the word "ONGOING"
n= 7
mO= 2
mN= 2
mG=2

