JSFiddle - React, Tailwind, and code Playground

by Harish Singh

HTML

InsPayNumber <input type="text" id="InsPayNumber" value="3" /> <br/>
InsurerInsPrice <input type="text" id="InsurerInsPrice" value="300" /> <br/>

HasInsPayWitTax <input type="checkbox" id="HasInsPayWitTax" value="1" /> <br/>

InsPayInstallmentPrice <input type="text" id="InsPayInstallmentPrice" /> <br/><br/>

JavaScript

$(document).ready(function () { 
    $('#InsPayNumber, #InsurerInsPrice, #HasInsPayWitTax').change(function () {
    var payNumber=  $('#InsPayNumber').val();
    var insurancePrice=  $('#InsurerInsPrice').val();


    if (payNumber!=null && insurancePrice!=null) {

        if (  $('#HasInsPayWitTax').checked) {

            $("#InsPayInstallmentPrice").val( ( insurancePrice*3/100)/payNumber);
        }else{
           $("#InsPayInstallmentPrice").val( insurancePrice/payNumber);
        }

    }else {
        $("#InsPayInstallmentPrice").val("");
    } 
    });

});