JSFiddle - React, Tailwind, and code Playground

by Serg Michael

HTML

<form id="year">
    <!--input type="text" name="" id="year_" value=5-->
    <input type="radio" id="radio-1" name="group" value="1"/>
    <input type="radio" id="radio-2" name="group" value="2"/>
    <input type="radio" id="radio-3" name="group" value="3"/>
  
  <div class="company">
    <select name="company" id="company">
      <option value="1500">1</option>
      <option value="5300">до 5</option>
      <option value="10100">до 10</option>
      <option value="12000">до 25</option>
      <option value="17000">до 50</option>
      <option value="0">50+</option>
    </select>
  </div>
  <br>
  <!--input type="label" id="mult" name="789" maxlength="300" readonly value=""><br-->
  <!--input type="label" id="itog" name="789" maxlength="300" readonly value=""-->
</form>
<div>
  Mult is: <span id="mnog">0</span>
</div>
<div>
  Sum is: <span id="itog">0</span>
</div>

JavaScript

(function ($) {
var year = $("#year");
    var company = +$('#company').val();
    var mnog = $("#mnog");
    var itog = $("#itog");
    var mult = 0;
    var result = 0;
    // Подписываемся на клик по форме и делегируем событие на элемент радио внутри формы с id radio-1
    year.on("click", "#radio-3", function (event) {
        mult = company*3;
        result = mult*.8;
     // alert (itog);
     		mnog.text(mult);
        itog.text(result);
    });
    year.on("click", "#radio-2", function (event) {
        mult = company*2;
        result = mult*.85;
     //   alert (itog);
     		mnog.text(mult);
        itog.text(result);
    });
    year.on("click", "#radio-1", function (event) {
    		mult = company;
        result = company;
     //   alert (itog);
     		mnog.text(mult);
        itog.text(result);
    });

 //mnog.text(mult);
 //itog.text(result);
 //alert (mnog);
})(jQuery);