In how many different ways can the letters of the word OPERATE be arranged?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 2520
Step 1: Count the total number of letters
The word OPERATE has 7 letters in total ($n = 7$).
Step 2: Identify repeating letters
Let's look at the frequency of each letter:
- O: 1
- P: 1
- E: 2 (repeats twice)
- R: 1
- A: 1
- T: 1
Step 3: Apply the Permutation Formula
The number of arrangements is given by:
$\frac{n!}{n_1! \times n_2! \times \dots \times n_k!}$
Where $n$ is the total number of letters and $n_k$ are the counts of repeating letters.
$\text{Number of ways} = \frac{7!}{2!}$
Step 4: Calculate the value
- $7! = 7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1 = \mathbf{5040}$
- $2! = 2 \times 1 = \mathbf{2}$
$\text{Total arrangements} = \frac{5040}{2} = \mathbf{2520}$