Discussion Forum
Que.  The set {1, 2, 3, 5, 7, 8, 9} under multiplication modulo 10 is not a group. Given below are four plausible reasons. Which one of them is false? 
a.  It is not closed 
b.  2 does not have an inverse 
c.  3 does not have an inverse 
d.  8 does not have an inverse 
Answer:3 does not have an inverse
