To determine the rank of the word "QUEUE" when all its letters are arranged in dictionary order, we need to systematically calculate the total number of permutations that precede it.
### Step 1: Understand the letters in "QUEUE"
The word "QUEUE" consists of the letters: Q, U, E, U, E.
There are 5 letters, with E appearing twice and U appearing twice.
### Step 2: Arrange letters in dictionary order
In alphabetical order, the letters are: E, E, Q, U, U.
### Step 3: Permutations starting with each letter
Let us compute the number of words starting with each letter until we reach "QUEUE".
#### Case 1: Words starting with "E"
If the first letter is "E", the remaining letters are: E, Q, U, U.
The total number of permutations of these letters is:
\[ \text{Permutations} = \frac{4!}{2! \cdot 2!} = 6 \]
This means 6 words start with "E" and precede "QUEUE".
#### Case 2: Words starting with "Q"
If the first letter is "Q", the remaining letters are: E, E, U, U.
The total number of permutations of these letters is:
\[ \text{Permutations} = \frac{4!}{2! \cdot 2!} = 6 \]
This means 6 words start with "Q".
#### Case 3: Words starting with "QE"
If the first two letters are "QE", the remaining letters are: E, U, U.
The total number of permutations of these letters is:
\[ \text{Permutations} = \frac{3!}{2!} = 3 \]
This means 3 words start with "QE".
#### Case 4: Words starting with "QUE"
If the first three letters are "QUE", the remaining letters are: E, U.
The total number of permutations of these letters is:
\[ \text{Permutations} = \frac{2!}{1!} = 2 \]
This means 2 words start with "QUE".
#### Case 5: Words starting with "QUEUE"
The word "QUEUE" itself is the next word.
### Step 4: Calculate the rank of "QUEUE"
- Words starting with "E": 6
- Words starting with "Q" but before "QUE": 6
- Words starting with "QE": 3
- Words starting with "QUE" but before "QUEUE": 2
- "QUEUE" is the next word.
The rank of "QUEUE" is:
\[ 6 + 6 + 3 + 2 + 1 = 18 \]
### Final Answer
The rank of the word "QUEUE" is:
d) 18th