edited by
1,184 views
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 $HK = \left\{hk : h \in H, k \in K\right\}$? 

  1. $72$
  2. $60$ 
  3. $48$ 
  4. $36$
edited by

1 Answer

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

edited by
Answer:

Related questions

1 votes
1 votes
0 answers
1
makhdoom ghaya asked Dec 17, 2015
366 views
Which of the following groups are isomorphic? $\mathbb{R}$ and $C$ $\mathbb{R}^{*}$ and $C^{*}$ $S_{3}\times \mathbb{Z}/4$ and $S_{4}$ $\mathbb{Z}/2\times \mathbb{Z}/2$ a...
2 votes
2 votes
4 answers
2
makhdoom ghaya asked Dec 17, 2015
2,707 views
Let $H_{1}$, $H_{2}$ be two distinct subgroups of a finite group $G$, each of order $2$. Let $H$ be the smallest subgroup containing $H_{1}$ and $H_{2}$. Then the order o...
1 votes
1 votes
0 answers
3
makhdoom ghaya asked Dec 17, 2015
566 views
Let $S_{n}$ be the symmetric group of $n$ letters. There exists an onto group homomorphism From $S_{5}$ to $S_{4}$ From $S_{4}$ to $S_{2}$ From $S_{5}$ to $\mathbb{Z}/5$F...
2 votes
2 votes
1 answer
4
makhdoom ghaya asked Dec 17, 2015
1,065 views
How many proper subgroups does the group $\mathbb{Z} ⊕ \mathbb{Z}$ have? $1$$2$ $3$ Infinitely many