JSFiddle - React, Tailwind, and code Playground

HTML

<span id="old-speed"></span><br />
<span id="new-speed"></span><br />

<button id="button-1" class="set-speed">Set speed to 10</button><br />
<button id="button-2" class="set-speed">Set speed to 20</button><br />
<button id="button-3" class="set-speed">Set speed to 30</button><br />

<button id="reset">Reset buttons</button>

JavaScript

var speed = 0;

function updateSpeed(s) {
    $('#old-speed').text('speed was: ' + speed);
    speed = s;
    $('#new-speed').text('speed is now: ' + speed);
    disableButtons()
}

function disableButtons() {
    $('button.set-speed').attr('disabled', true);
}

function enableButtons() {
    $('button.set-speed').attr('disabled', false);
}

$('#button-1').click(function() {
    updateSpeed(10);
});

$('#button-2').click(function() {
    updateSpeed(20);
});

$('#button-3').click(function() {
    updateSpeed(30);
});

$('#reset').click(function() {
    enableButtons();
});