In how many different ways can letters of the word OFFICES be arranged?

Answer: Option A

The given word contains 7 letters of which F is taken 2 times.
∴ Required number of ways
$$\begin{array}{rl}& =\frac{7!}{2!}\\ & =\frac{7\times 6\times 5\times 4\times 3\times 2\times 1}{2\times 1}\\ & =2520\end{array}$$