Consider the sets

$\phi, A=\{1,3\}, B=\{1,5,9\}, C=\{1,3,5,7,9\}$

Insert the symbol $\subset$ or $ \not\subset $ between each of the following pair of sets:

$\phi \,....\,B$

Write the following sets in the set-builder form :

$\{ 2,4,6 \ldots \} $

State whether each of the following set is finite or infinite :

The set of letters in the English alphabet

Which of the following are sets ? Justify your answer.

The collection of all the months of a year beginning with the letter $\mathrm{J}.$

Let $A=\{a, e, i, o, u\}$ and $B=\{a, b, c, d\} .$ Is $A$ a subset of $B ?$ No. (Why?). Is $B$ a subset of $A ?$ No. (Why?)

State which of the following sets are finite or infinite :

$\{ x:x \in N$ and $2x - 1 = 0\} $