toggleClass Speed Test

Which is faster?
Case 1:
	for(var i=0;i<10000;i++){
		$("#div"+i).toggleClass("selected",true);
	}
Case 2:
	for(var i=0;i<10000;i++){
		if($("#div"+i).is("selected"))
			$("#div"+i).toggleClass("selected",true);
	}
Case 3:
	divs.find(".selected").toggleClass("selected",true);

In the following test I create ten-thousand divs. Every fifth div has a 'class="selected"' attribute. I am running three tests above on all the classes.