The number of subgroups of the group $(Z_{5}, +_{5})$ is

Write the following set in roster form:
$A = \{ x : x \text{ is an integer and } -3 < x < 7 \}$

Write down all the subsets of the following set: $\{a\}$

Two finite sets have $m$ and $n$ elements respectively. The total number of subsets of the first set is $56$ more than the total number of subsets of the second set. The values of $m$ and $n$,respectively are

If $A = \{1, 2, 3, 4, 5, 6\}$, then which of the following is not true (in $in A$)?

Find the union of each of the following pairs of sets:
$A = \{ x : x \text{ is a natural number and a multiple of } 3 \}$
$B = \{ x : x \text{ is a natural number less than } 6 \}$