JSFiddle - React, Tailwind, and code Playground

HTML

<div class="image">
    <img class="large" src="images/iphone3g.png" alt="iphone3g" width="141" height="141" />
</div>

<form name="iphone3g">
    <input type="checkbox" name="iphone3g1" value="50.00"> Vidro Partido<br />
    <input type="checkbox" name="iphone3g2" value="59.00"> LCD Danificado<br />
    <input type="checkbox" name="iphone3g3" value="80.00"> Substituir capa traseira<br />
    <input type="checkbox" name="iphone3g4" value="38.00"> Botão Volume    
    
    <div class="image">
        <img class="large" src="images/iphone3gs.png" alt="iphone3g" width="141" height="141" />
    </div>
    
    <input type="checkbox" name="iphone3gs1" value="60"> Vidro Partido 3GS<br />
    <input type="checkbox" name="iphone3gs2" value="69"> LCD Danificado 3GS<br />
    <input type="checkbox" name="iphone3gs3" value="89"> Substituir capa traseira 3GS<br />
    <input type="checkbox" name="iphone3gs4" value="45"> Botão Volume3GS
    
    <div class="image">
        <img class="large" src="images/iphone4.png" alt="iphone3g" width="141" height="141" />
    </div>
    
    <input type="checkbox" name="iphone41" value="169"> Vidro/LCD Partido<br />
    <input type="checkbox" name="iphone42" value="99"> Substituir capa traseira<br />
    <input type="checkbox" name="iphone43" value="79"> Botão Volume<br />
    <input type="checkbox" name="iphone44" value="76"> Botão Home
    
</form>

JavaScript

$(document).ready(function() {
    $("input:checkbox").click(function() {
        var checked = $("input:checked").length;
        alert(checked);
    });
});