Let b be the number of cards Kenny originally owned.
Since he sold 82 cards, this means that he has :
[tex]b-82[/tex]We know that he still has 159 cards left, that means that:
[tex]b-82=159[/tex]Now we solve it:
[tex]\begin{gathered} b-82=159 \\ b=159+82 \\ b=241 \end{gathered}[/tex]Therefore, he originally had 241 baseball cards.