jquery find first child with class tr and td class code example
Example 1: select 2nd td jquery
$(".location table tbody tr td:first-child").addClass("black");
$(".location table tbody tr td:nth-child(2)").addClass("black");
Example 2: jquery select the 3rd row of a table
$('.itemTable').eq(2);
//this will grab the 3rd row of the table with the class itemTable