Given word is "centurion".
Now we have to find the ratio of the letter n to the letter o in the given word.
To do that first we need to cound how many times letters "n" and "o" repeat.
Number of times letter "n" appears in the given word = 2
Number of times letter "o" appears in the given word = 1
Then ratio of the letter n to the letter o in the word centurion will be 2:1.
Hence final answer is 2:1.
