Which type of letter is not likely to be formal?

Question

Question: Which type of letter is not likely to be formal?

Options:

1.  Making a booking
2.  Confirming an interview date
3.  Making a complaint
4.  Email to a friend

Answer 1

4. Email to a friend

'Email to a friend' letter is not likely to be formal.

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Explanation:

An informal letter is a personal letter type which we usually use to write to our friends, family or relatives.

So, writing an email, letter.. etc to a friend, family or relative is not likely to be formal. That would be informal.