How to get Addition of multiple textbox's values in another single textbox using jQuery?

Newbie in jquery, need some help with this description.

Suppose, I have 1 textbox that contain the result of Addition of another 2 textbox's.

<input type="text class="tb1">
<input type="text class="tb2">
<input type="text class="result" id="result1">

like this.

Suppose I have 5 textbox's that contain their individual 2 textbox's addition results. Each Result textbox generate result automatically using jquery script. So, I have 5 result textbox's with their respective addition result.

Now, I want to sum of the values in all 5 result texbox's again in another textbox when i click on checkbox automatically by using jquery or javascript script.

How can I achive this task ? refer image for understanding of question. http://ift.tt/1SKJVJn