Which of the following sets is finite or infinite?
The set of months of a year.

If $A = \{ 1, 2, 3, 4, 5 \}$,then what is the number of proper subsets of $A$?

Make correct statements by filling in the symbols $\subset$ or $\not\subset$ in the blank spaces:
${ x:x \text{ is an even natural number} } \dots { x:x \text{ is an integer} }$

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

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

State whether the following set is finite or infinite:
The set of letters in the English alphabet.