Powerpoint 2010-can I password protect just a few slides in the presentation

[hellohello1]

Hello,
I'm using Powerpoint 2010.

I have a powerpoint presentation used for a training class. The presentation contains 'knowledge quizzes' to test students. I'm struggling on where to have the answer key slides.

All the students are emailed the powerpoint presentation before the class.

I thought of hiding the slides, but the students would still be able to see the hidden slide in ppt view. I thought of creating 2 powerpoints: one for the teacher and one for the students, but that would require maintaining 2 presentations.

Is there any way to password protect just a few slides in a presentation?

Thanks