3 votes 3 votes Let $G$ be a group and let $H$ and $K$ be two subgroups of $G$. If both $H$ and $K$ have $12$ elements, which of the following numbers cannot be the cardinality of the set $HK = \left\{hk : h \in H, k \in K\right\}$? $72$ $60$ $48$ $36$ Set Theory & Algebra tifrmaths2014 set-theory&algebra group-theory + – makhdoom ghaya asked Dec 17, 2015 • edited Aug 18, 2020 by soujanyareddy13 makhdoom ghaya 1.2k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
1 votes 1 votes I think 60 is not be the cardinality of the set HK explanation cardinality of set HK= 144 (H=12 ,K=12) and subgroup is the divisor of the group so that 1:144/72=2 2:144/60=2.4 3:144/36=4 4:144/48=3 Rackson answered Nov 18, 2018 • edited Nov 18, 2018 by Rackson Rackson comment Share Follow See all 0 reply Please log in or register to add a comment.