html
html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
<!DOCTYPE html>
<html>
<head>
<title>Math challenge</title>
<link href="https://fonts.googleapis.com/css?family=Dosis" rel="stylesheet">
<link href="https://fonts.googleapis.com/css?family=Ubuntu+Mono" rel="stylesheet">
</head>
<body>
<div id="top">Is the number</div>
<div id="left">2
<span></span><b> - 2009</b>
<div id="right"> - 1</div>
</div>
<div id="bottom">divided by 1155?</div>
<input type="checkbox" id="show">
<label for="show">Show me the answer, I don't want to think</label>
<pre>
YES, DIVIDED.
The number of the form:
(2^k) - 1 is divided by 3:
if and only if when k is even;
by 5 - when k is a multiple of 4;
by 7 - when k is a multiple of 3;
by 11 - when k is a multiple of 10;
Enter to Rename, Shift+Enter to Preview
css
css
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
body {
background: #55eeff;
font-family: 'Dosis', sans-serif;
font-weight: 600;
color: #456;
margin: 0 auto;
}
div {
border-bottom: 1px solid #456;
font-size: 2.4rem;
padding-top: 50px;
position: relative;
}
div#bottom, div#top {
text-align: center;
margin-bottom: 40px;
}
div#left span:after{
content: '+ 3';
position: absolute;
top: 25px;
left: 115px;
}
div#left span:before{
content: '2008';
Enter to Rename, Shift+Enter to Preview
js
js
1
Enter to Rename, Shift+Enter to Preview
BROWSER
Console
Run