I didn't see the entire code, but at first glance, there is some redundancy in there.

For example, this piece of code:

    $(function() {
        $("#word1a").click(function() {
            $("#word1b").css("text-decoration", "line-through").css("opacity", "0.2").css("color", defaultTextColor);
            $("#word1a").css("text-decoration", "none").css("opacity", "1").css("color", defaultTextColor);
            $("#slash1").css("text-decoration", "line-through").css("opacity", "0.1");
            saveanswers();
        });
    
        $("#word1b").click(function() {
            $("#word1b").css("text-decoration", "none").css("opacity", "1").css("color", defaultTextColor);
            $("#word1a").css("text-decoration", "line-through").css("opacity", "0.2").css("color", defaultTextColor);
            $("#slash1").css("text-decoration", "line-through").css("opacity", "0.1")
            saveanswers();
        });
    
        $("#word2a").click(function() {
            $("#word2b").css("text-decoration", "line-through").css("opacity", "0.2").css("color", defaultTextColor);
            $("#word2a").css("text-decoration", "none").css("opacity", "1").css("color", defaultTextColor);
            $("#slash2").css("text-decoration", "line-through").css("opacity", "0.1");
            saveanswers();
        });
    
    
        $("#word2b").click(function() {
            $("#word2b").css("text-decoration", "none").css("opacity", "1").css("color", defaultTextColor);
            $("#word2a").css("text-decoration", "line-through").css("opacity", "0.2").css("color", defaultTextColor);
            $("#slash2").css("text-decoration", "line-through").css("opacity", "0.1")
            saveanswers();
        });
    
        $("#word3a").click(function() {
            $("#word3b").css("text-decoration", "line-through").css("opacity", "0.2").css("color", defaultTextColor);
            $("#word3a").css("text-decoration", "none").css("opacity", "1").css("color", defaultTextColor);
            $("#slash3").css("text-decoration", "line-through").css("opacity", "0.1");
            saveanswers();
        });
    
    
        $("#word3b").click(function() {
            $("#word3b").css("text-decoration", "none").css("opacity", "1").css("color", defaultTextColor);
            $("#word3a").css("text-decoration", "line-through").css("opacity", "0.2").css("color", defaultTextColor);
            $("#slash3").css("text-decoration", "line-through").css("opacity", "0.1")
            saveanswers();
        });
    
    }); 

Can be shortened to this:

    $(".word").click(function () {
        var clickedID = $(this).attr("id");
        var other = 'b';
        if(clickedID[1] != 'a'){
            other = 'a';
        }
        $(this).css("text-decoration", "none").css("opacity", "1").css("color", defaultTextColor);
        $("#" + clickedID[0] + other).css("text-decoration", "line-through").css("opacity", "0.2").css("color", defaultTextColor);
        $("#slash" + clickedID[0]).css("text-decoration", "line-through").css("opacity", "0.1");
        saveanswers();
    });

[Here's a fiddle that demonstrates what I mean](http://jsfiddle.net/qfBqT/) 

Hope this helped.  Feel free to ask if you have any questions. :)