No, there won't. /No, there won't be. Short answers.

[wolfbm1]

Hello.

A. Will there be many old people in the crowd?
B. No, there won't be. (There will be mostly young people.)

I wonder if the short answer above is correct. Can I leave out the verb 'be'?

 

[Biffo]

A. Will there be many old people in the crowd?

B1. No, there won't be many old people in the crowd.
B2. No, there won't be many old people.
B3. No, there won't be many.
B4. No, there won't be.
B5. No, there won't.
B6. No.

All of the above are possible.

 

[wolfbm1]

Thank you, Biffo.

 

[WildWest]

I would go with the B5 as a non-native. It's what was in my mind when I saw the thread.

 

[wolfbm1]

I have just learned that B5 and B6 are simple confirmations. B1 to B 4 could be used for emphasis.
The simple past version of the conversation in post #1 is then:

A1. Were there many old people in the crowd?
B1. No, there weren't. (There were mostly young people.)

This time there is not an auxiliary verb in that question.
So, if we want to make a simple confirmation, we just say yes, or 'yes + a pronoun + an auxiliary verb.'
When the verb "be" does not have an auxiliary, we repeat the appropriate form of "be."