Question

Show that set $B=\{y:2y+1<3andy\in W\}$ is a singleton set.

Answer 1

$B=\{y:2y+1<3andy\in W\}2y+1<3\Rightarrow 2y+1-1<3-1\text{(Subtracting 1 from both sides)}\Rightarrow 2y<2\Rightarrow y<\frac{2}{2}\text{(Dividing both sides by 2)}\Rightarrow y<1\therefore B=\left\{0\right\}\text{Hence set B is a singleton set.}$