Problem Writing Party: May 5th to May 20th

Hello, Brilliant!

Thanks to everyone for your magnificent contributions to the previous problem writing parties.

As always, we're going to continue showing off the hard work these members of the community put in over the last week, so Brilliant will featuring these quizzes in topic listings and social media. Now that those announcements have been made, we're moving on to our seventh Problem Writing Party!

How it Works

The party starts right now (May 5th, 2016) and will last for the next two weeks. Throughout the two weeks, we will be focusing on writing awesome problems for the topics listed in quizzes that need your help on the publish page.

To join, submit as many problems as you want to these listed topics. At the end of the party, Brilliant staff will be picking the best 5-10 problems for each topic. These problems will then be immortalized and formed into a challenge quiz. If we pick your problem, then you can brag to your friends because it will be displayed on Brilliant forever! Your problem has a better chance of being selected if you include a graphic (when appropriate) and a solution.

Use this note to

Ask questions about the party or brainstorming ideas from Brilliant staff.
Share links to great relevant problems.
Bounce your ideas off each other to help formulate the best problem you can.

To be selected, problems you submit should be fun and challenging to a student in levels 1-3 for the given topic.

-------->This Party's Topic Listing<--------

The topics of problem submission for this party can be found by navigating over to the Brilliant publish page and checking under the quizzes that need your help section. Just click the contribute button next to the topic you want make a submission to.

Happy writing and continue to party on!

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

In a room there are 15 switch on a wall out of which only two are fan switch.In how many minimum no of ways a person can find which are the correct switches of each fan.

nikhil ahluwalia - 5 years, 1 month ago

Can you post this as a problem?

Sandeep Bhardwaj - 5 years, 1 month ago

105 ways? 15C2

ishan pradhan - 5 years, 1 month ago

My entry for floor and ceiling functions I'm floored

And A force of different kind for acceleration , velocity ,displacement

pouring out powers of 2 and 3 for distribution in bins

no. of solutions for graph sketching

neelesh vij - 5 years, 1 month ago

All the problems are great. Thanks for such a wonderful contribution. :)

Hope to get more from you. @neelesh vij

For introduction to recursion: Calculus and Computer Science Again . I know it's kinda more like for Comp. Sci. but still, it is good practice for recursion.

Kunal Verma - 5 years, 1 month ago

Your link is placed wrongly. [word] followed by (website link)

Hung Woei Neoh - 5 years, 1 month ago

Thanks. c:

So I'm curious...

When you submit a question, it would be nice to see the "incorrect" answers that are submitted.

That way, if you keep seeing the same "incorrect" answer, you would have an early heads up to either (a) clarify the wording in the question, or (b) update the answer. (Maybe all those answers are correct and its me who goofed up with my answer! :P )

Geoff Pilling - 5 years ago

I agree with you!

Prince Loomba - 5 years ago

Yeah, I'd hate for great problems to go to waste just because they aren't well explained, or we happened to get the wrong answer in there.

@Geoff Pilling – Same with me

@Prince Loomba – For example, this question: Guess that number!
39 viewers, 7 attempts and 0 solvers

Given the caliber of 39 random people on Brilliant, I doubt that no one would have solved it.

So, I am wondering whether some of those 7 attempts might actually be correct, but I just goofed up... (Wouldn't be the first time! :P )

And, I figure I need to get it fixed up quickly if so, since the questions have a shelf life of about 3-4 days. If they don't get some kind of action by then, it seems they are very likely to go into the vast wasteland of forgotten questions! :-/

@Geoff Pilling – It is written error 404 cant open. Please use latex for the link. Sorry

@Prince Loomba – Ooops... There. I fixed it.

@Geoff Pilling – Very good question

@Prince Loomba – Hey thanks, Prince! :^)

@Geoff Pilling – And please explain how did you get the relation between N H L

@Prince Loomba – Well I figure every time you take a guess, you divide the problem up into two new problems... One where you reduce your number of "too low" guesses by 1, and one where you reduce your number of "too high" guesses by 1. And, the number of N is either all the ones above your guess or all the ones below your guess. So, the recursive equation can be defined as follows:

Let $N(H,L)$ = The maximum number you can accomplish this in given that you can get only get $H$ "too high"s and $L$ "too low"s, then...

$N(0,L) = L+1$

$N(H,0) = H+1$

$N(H,L) = 1 + N(H-1,L) + N(H,L-1)$

@Geoff Pilling – Okay. Now its clear. Please mention that in original solution too.

@Prince Loomba – Good suggestion, Prince... Done.

@Geoff Pilling – Oh thanks for the comment☺

@Geoff Pilling – Here is my question too. 45 views 5 attempts 1 solver Log

@Prince Loomba – OK, I'll take that as a challenge and take a look! :)

@Geoff Pilling – How was the question?

@Prince Loomba – Haha.... Pretty tough... I'll need to think about it a little more! :)

@Geoff Pilling – If you get it wrong try this. Please do not consider it same. Theres a difference between these

@Geoff Pilling

If you think that the problem needs to be clarified or the given answer is incorrect, then you should report the problem. And the staff can look into the details.

Thanks!

Sandeep Bhardwaj - 5 years ago

For logical reasoning topic, we need problems mainly on Truth Seeking subtopic. Thanks!

This easy problem on floor from my side sir

Gauri shankar Mishra - 5 years, 1 month ago

To my surprise u have reposted this question sir !!!!!!!!

@Sandeep Bhardwaj Sir . This is my submission for Truth Seeking subtopic. A total of 6 problems.

Abhay Tiwari - 5 years, 1 month ago

My submissions Math Archive (13)

Math Archive (14)

Shivam Jadhav - 5 years, 1 month ago

Woo hoo... Sounds good! Looking forward to some great problems! :) (I'll try writing some as well)

Geoff Pilling - 5 years, 1 month ago

Here is my contribution for the acceleration one.

Tanishq Varshney - 5 years, 1 month ago

Here's my entry: Logic-puzzle-Sphinx's Riddle, Who stole my walnuts?, Dark Room Hunt, Cat's Logic

Combinatorics-Distribution to the Bin-Is your date odd or even?, Fruit Lovers.

Worranat Pakornrat - 5 years, 1 month ago

2 questions for the topic: Function graphs.

Here and here

So, should we write new problems for these pages, or use ones we've already published?

My entries for Logic 1 Logic 2 Logic 3

This is my new one for Combinatorics-Recurrence Incursion: Wire Hive.

Here is a question on recursion

Prince Loomba - 5 years, 1 month ago

a problem about decimals

Margaret Zheng - 5 years, 1 month ago

My first problem here.

Decimals Warmup

Lee Care Gene - 5 years, 1 month ago

Who can swim?

Hua Zhi Vee - 5 years, 1 month ago

Here are two submissions for logic: 1) A Murder Mystery Game 2) Alien Abduction Problem

My entry for Velocity and Acceleration

Joao Miguel Coelho - 5 years, 1 month ago

Count me in with this classic piece of calculus-1920 Calculus Horror

Anshuman Singh Bais - 5 years, 1 month ago

Hi Anshuman. Nice problem! You can make your comment formatted more nicely by the following:

$\text{[Paste problem title here](Paste URL link for problem here)}$

Hobart Pao - 5 years, 1 month ago

Done Thanks

My entries will be listed here.

Nice problem! I hope you to increase the number of entries listed here. ;)

Thanks. I'll try but still have many exams coming up.

My submission for curve sketching : Desmos is for donkeys

Rohit Ner - 5 years, 1 month ago

Wonderful problem! I loved this problem very much. Thanks for sharing this!

Waiting for more problems. @Rohit Ner

My entry is for complex numbers: A Problem in Complex Numbers!

Miraj Shah - 5 years, 1 month ago

The problem is good. But it is not from the topic listing of this party. Thanks for the problem and I'm excited to get awesome problems from the topic listing for this party.

I am extremely sorry for the late entry, it is because I have not opened brilliant for a week in between and I just opened today. As I saw the party ends on the day of my last important entrance examination for college. I am posting a problem now, and will be back in the 18th with a lot more.

Weigh it out

Unique Decimal

On function graphs

Soumava Pal - 5 years, 1 month ago

You have interchanged the brackets!

Yea sorry, I forgot all my LateX in all this pressure with the exams. :p

@Soumava Pal

Great problem! Waiting for more problems as soon as you get done with your exams.

All the best for your exams!

Parabola : https://brilliant.org/problems/interesting-parabola/

Basics in Area : https://brilliant.org/problems/just-two-lines/

Akash Shukla - 5 years, 1 month ago

Here's my new one for Combinatorics-Distribution into Identical Bins: The pawn can't stand alone.

A great one as usual. ;)

Thanks Dr. Warm! Waiting for more. :P

Thanks! Looking forward to it, too. 😉

Here is my question for logic

Great! Thanks Prince for an awesome problem.

Waiting to see more of your awesome problems. :)

My problem for combinatorics expected value: A surprising invention. My problem for combinatorics recurrence relations:The Chase of Doom

Www Www - 5 years, 1 month ago

Nice problem! @Www Www

You can display the link of your problem by using the syntex: [Name of the problem] (link of the problem) and then your link will be displayed as Name of the problem.

Excited to get more such great problems on your behalf. Thanks!

THIS is a fresh ceiling problem ;D

Nice problem, Margaret! Thanks!

Waiting for more from your side. ;)

Thanks and I will keep working:) My exams are coming up next week so I am trying my best.

Margaret Zheng - 5 years ago

1 2. 2 problems on distances, velocity, acceleration..

Sparsh Sarode - 5 years, 1 month ago

displacement when v=0 problem on displacement and velocity

My contribution to floor and ceiling functions: A road with holes

An interesting logic problem,a challenging one

My submission is "TEDIOUS I"

https://brilliant.org/problems/tedious-i/

Aakash Khandelwal - 5 years, 1 month ago

A graph problem

My submission for decimals. : Working out with decimals!

My question on floors and ceilings.

Don't Get Confused!

(sine)ing a problem on displacement, acceleration, velocity

Sparsh Sarode - 5 years ago

My entry for complex numbers and binomial theorem (I still solve some): Ouch...

敬全钟 - 5 years ago

My new one for Function-Graphs: Double Crosses

Worranat Pakornrat - 5 years ago

Another problem on displacement, velocity, acceleration can u average (sine)ing function?

Here is my problem on displacement, velocity and acceleration topic - Desing of the car is a wow.

New one for Combinatorics-Expected value: Double Gamble.

What is the maximum powers of 2 that 10 raised to 10 can divide without decimals?

Lance Fernando - 5 years ago

My entry for Floor and Ceiling Functions: That's actually really cool!.

My entry for Decimals: Decimals, Fractions, Scientific Notation and Percentages?!.

Sharky Kesa - 5 years, 1 month ago

A hard logic puzzle

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}`	$\boxed{123}$