Preposition and Ellipsis

[Brahman]

In the following sentences, is there a need for a preposition before the expression "the same week". And, could the word "following" stand alone?

1. Our exams' results will be out on 27th July. Could we meet you for a consultation either the same week or the following?

2. Our exams' results will be out on 27th July. Could we meet you for a consultation either in the same week or in the following week?

3. Our exams' results will be out on 27th July. Could we meet you for a consultation either in the same week or the following week?

I thank you for your help.

[Alan]

All possible, but #1 is perfectly adequate for normal informal use.