The number of elements in the set $\{ (a,\,b):2{a^2} + 3{b^2} = 35,\;a,\,b \in Z\} $, where $Z$ is the set of all integers, is
Which of the following is the empty set
State which of the following sets are finite or infinite :
$\{ x:x \in N$ and $2x - 1 = 0\} $
List all the elements of the following sers :
$E = \{ x:x$ is a month of a year not having $ 31 $ days ${\rm{ }}\} $
List all the elements of the following sers :
$F = \{ x:x$ is a consonant in the Englishalphabet which precedes $k\} $