Given: We have 6 letters

To Find: Number of ways to arrange letters P,E,N,C,I,L

Condition: N is always next to E

Here we need EN together in all arrangements.

So, we will consider EN as a single letter.

Now, we have 5 letters, i.e. P,C,I,L and ‘EN’.

5 letters can be arranged in

⇒

⇒

⇒ 120

In 120 ways we can arrange the letters of the word ‘PENCIL’ so that N is always next to E