You will find them on KVPY home page maybe in a week's time or later in November as there is a retest on November 19, 2017 for a few candidates who faced technical issues at certain centers and could not finish the paper. Keep checking the website. Scroll down the home page and you will find previous years papers with answer keys. 2017 question paper with answer key should be up soon.

http://www.kvpy.iisc.ernet.in/main/index.htm