Q:

'Were' or 'are' in the conditional tense? 

I am not sure how a sentence I want to write should be written:

I would choose the apple in the case where an unknown number of apples were to be stored in the box. 
I would choose the apple in the case where an unknown number of apples are to be stored in the box. 

Should I write were or are, please? 
I am new to this forum, so I apologise if this question has been asked before. 
Furthermore, I apologise if I have not correctly worded my question. 

A:

First sentence is correct because it is Second Conditional with construction of if + were to + plain form + would + present infinitive such as in the sentence

If we were to answer that question, I don't know what we would say. 