Problems Selected by Brilliant Staff: Feb. 11, 2019

Although we have discontinued "Problems of the Week," we're excited to continue showcasing the problem-writing skills of our community. We wanted to share with you these fifteen wonderful problems written solely by members of the community. We have placed these problems in our various "Challenge Quizzes" so that they can featured on our site and accessible to the community in the future.

Here is the list of the problems for you all to try:

Geometry Level 1: Folding a rectangular sheet of paper by Ronald Chén
Classical Mechanics Level 2: Gravitational Field! by Niraj Sawant
Logic Level 2: Burglars and Detectives Part1 by Jay B
Algebra Level 2: The Horse and the Donkey by Jay B
Electricity and Manetism Level 3: A Flux Divided by Steven Chase
Discrete Mathematics Level 3: Number of Shoes by Mk Jain
Geometry Level 3: Triangulations by Otto Bretscher
Logic Level 3: Logic Thinks by Winston Choo
Number Theory Level 3: Sum and sum to the seventh power by Sathvik Acharya
Classical Mechanics Level 3: Rod on a Hemisphere by William Allen
Geometry Level 3: Triangles and squares by Ronald Chén
Algebra Level 4: Roots and its Relations by Sathvik Acharya
Number Theory Level 4: 3 Brothers Riddle by Worranat Pakornrat
Logic Level 4: The smileys problem by Chan Lye Lee
Discrete Mathematics Level 5: Average Floor Number of an Elevator? by Garrett Clarke

Markdown

Appears as

*italics* or _italics_

italics

**bold** or __bold__

bold


- bulleted
- list

bulleted
list


1. numbered
2. list

numbered
list

Note: you must add a full line of space before and after lists for them to show up correctly

paragraph 1

paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)

example link

> This is a quote

This is a quote

    # I indented these lines
    # 4 spaces, and now they show
    # up as a code block.

    print "hello world"

# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"

Math

Appears as

Remember to wrap math in $ ... $ or \[ ... \] to ensure proper formatting.

2 \times 3

2 \times 3

2^{34}

2^{34}

a_{i-1}

a_{i-1}

\frac{2}{3}

\frac{2}{3}

\sqrt{2}

\sqrt{2}

\sum_{i=1}^3

\sum_{i=1}^3

\sin \theta

\sin \theta

\boxed{123}

\boxed{123}

Easy Math Editor

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

Markdown	Appears as
`italics` or `_italics_`	italics
`bold` or `__bold__`	bold
- bulleted - list	bulleted list
1. numbered 2. list	numbered list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1 paragraph 2	paragraph 1 paragraph 2
`[example link](https://brilliant.org)`	example link
`> This is a quote`	This is a quote
# I indented these lines # 4 spaces, and now they show # up as a code block. print "hello world"	# I indented these lines # 4 spaces, and now they show # up as a code block. print "hello world"

Math	Appears as
Remember to wrap math in `$` ... `$` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$

Comments

I'm curious... Why we're the problems of the week discontinued?

Geoff Pilling - 2 years, 3 months ago

Over time, we discovered that most users were drawn towards highly curated learning experiences like our courses. We wanted the free experience on our site to be aligned with this demand, so we created Daily Problems. The Problems of the Week were a tremendous success, but the user base for them stagnated over time. We found that the PotW format had a limited audience because it was too a la carte -- it wasn't well-connected. You either knew how to do the problems or you didn't, and there was not enough guidance on how to achieve understanding if you didn't.

It took a substantial amount of effort to curate the Problems of the Week. We feel like the Daily Problems add more value for our users instead. Right now, we're focused on creating engaging learning experiences through our courses and Daily Problems, and in the future we're hoping to maintain a great community experience, but to do more to connect these community features to our guided experiences.

Andrew Hayes Staff - 2 years, 3 months ago

@Andrew Hayes, why not one science AND one math problem every day for daily challenges?

Mahdi Raza - 1 year, 3 months ago

In resharing problems of mine from years ago so that newer members can give them a try, I've ended up monopolizing the Popular section of the Community page. Is there any way short of deleting my problems to remedy this unintended consequence? The Popular section doesn't seem to refresh that regularly.

Brian Charlesworth - 2 years, 3 months ago

To Brian's point, if all that gets posted are Brian's problems, then what about Brian? Where does he go to see the new and challenging problems? 😯

Hahaha Yes, what about Brian? I always go to the New section anyway to test out those problems and report if necessary, or dip into my Saved collection. But the Popular section questions get the most attention on the Community page, so I think it would be better if the algorithm used could be adjusted so that the list of questions in that section was refreshed more regularly. Even before my recent unintended monopolization I did notice that the Popular list was relatively stagnant. Any thoughts on the matter? I apologize if the current status of this section has annoyed you at all; I just thought newer members would enjoy trying out my old problems. It seemed like a good idea at the time. :/

@Brian Charlesworth – Just to chip in - there's certainly a noticeable trend in the Popular list at the moment, but if you still have problems to put up, please continue! I for one have really enjoyed the selection you've posted so far - well written, interesting and in a wide variety of different topics (which, succinctly, is what I am currently missing about the Problems of the Week). And yes, what about Brian? The New section is good, but it's pretty wild out there. I hope the algorithm reinvigorates the Popular section soon but in the meantime am extremely happy to see you are keeping it going.

Chris Lewis - 2 years, 3 months ago

@Chris Lewis – I agree. Brian's problems are some of the best on Brilliant! 😃

And not only that but if you write a problem, he'll more often than not take it to the next level!

@Geoff Pilling – Thanks, Geoff and Chris, for the encouragement! I would like to keep resharing old problems, but I think I'll wait to hear from @Andrew Hayes before continuing. I don't want to ruffle any feathers with staff (or other members), so I would like to hear first about their thoughts on the present situation and also on any plans they have to "reinvigorate the Popular section" (as Chris so aptly states).

I don't think it's such a terrible thing that your high quality problems from yesteryear are showing up again. I do see how they're monopolizing the space, however. Unfortunately, I don't think we'll be making any changes to our algorithm any time soon, but I will see if we can do more to popularize other problems so that your problems aren't hogging the spotlight.

Thanks, Andrew, for the response and proposed action. :)

cc @Julian Poon since this might be interesting to you based on your comment in the other discussion.

Silas Hundt Staff - 2 years, 3 months ago

Wouldn't there be more additions?

Mr. India - 2 years, 1 month ago

I hope so! :)

Geoff Pilling - 2 years, 1 month ago

Math	Appears as
Remember to wrap math in `\(` ... `\)` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$