<!DOCTYPE html>

<html>

<head>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>

<script>

$(document).ready(function () {

$("#setCssBtn").click(function () {

$("p").css({ "background-color": "#ace60e", "font-size": "210%" });

});

$("#removeStylesBtn").click(function () {

$("p").removeAttr("style");

});

});

</script>

</head>

<body>

<h2>This is a heading</h2>

<p style="background-color:#ff0000">This is a paragraph 1.</p>

<p style="background-color:#00ff00">This is a paragraph 2.</p>

<p style="background-color:#0000ff">This is a paragraph 3.</p>

<p>This is a paragraph 4.</p>

<button id="setCssBtn">Set multiple styles for p</button>

<button id="removeStylesBtn">Remove multiple styles</button>

</body>

</html>