Answer :
The non-negative one-digit numbers are
[tex]0,1,2,3,4,5,6,7,8,9[/tex]Since the elements of set A has to be greater than zero, the elements of such a set are
[tex]A=\lbrace1,2,3,4,5,6,7,8,9\rbrace\rightarrow9\text{ elements}[/tex]
The non-negative one-digit numbers are
[tex]0,1,2,3,4,5,6,7,8,9[/tex]Since the elements of set A has to be greater than zero, the elements of such a set are
[tex]A=\lbrace1,2,3,4,5,6,7,8,9\rbrace\rightarrow9\text{ elements}[/tex]