There are `7` letters in the word CLIFTON.
So, there are total `7!` ways of arranging these letters.
Now, we have to find number of ways that the two vowels come together.
We can consider these two vowels as a single entity as they will always be together.
So, we can arrange the word in `6!` ways.
When the two vowels `I` and `O` are together, we can arrange these vowels in `2!` ways.
So, there are total `6!xx2!` ways in which two vowels can come together.
`:.` The required probability `= (6!xx2!)/(7!) = 2/7.`