Depends on a few things.
If we're talking a quiz or some sort of application where the answers should have some secrecy, then you're probably not going to want to merely hide / show them.
If that doesn't matter, then simply revealing the new question and results as the user goes along might be best, no new requests, limited potential for delays in the experience
That is, assuming we're not talking a million different questions that might make the initial load a bit heavy. As +Jordan Hurt
said, Ajax calls would work well in that case where you simply fetch the desired questions as needed.