What pattern of ZMQ must be used for the following scenario?

I have started learning ZMQ (Python) very recently. I must admit, I am finding it hard to understand PUSH/PULL and DEALER/ROUTER patterns.

My problem statement is the following:

1. N number of Client's (e.g. 100) will send request (query for some data, access a resource, etc) at 10:00:00 (hr:min:sec) AM
2. Server must process all the N Request at 10:00:00 AM.
3. Assume that a request takes 30 Seconds to complete, all the client's (100) must receive the response at 10:00:30 AM
4. What pattern of ZMQ should I use ?

I understood that REQ/REP is synchronous and I can't use that pattern to solve the particular problem. (Server can process only one request at a time)

Please help me with a sample program/link to develop a client/server application using ZMQ. ( Server must at least process 100 requests at a time)

If the number of request's increases next day, will I be able to scale using ZMQ?
If yes, how?