If $aN = \{ax : x \in N\}$ and $bN \cap cN = dN$,where $b, c \in N$ are coprime numbers,then:

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

In this question,all integers are represented in base $10$. Consider the set $E$ of positive integers $n$ having the property that when any nonzero digit $d \in \{1, 2, \dots, 9\}$ is written to the right of $n$,the resulting number is divisible by $d$. Let $N$ be the smallest element of $E$. The product of the digits of $N$ is:

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

Which of the following is an example of the null set?
$\{ x : x \in \mathbb{N}, x < 5 \text{ and } x > 7 \}$

If $A = \{1, 2, 3, 4, 5, 6\}$, then which of the following statements is false?