## Search found 90 matches

Thu Aug 04, 2016 7:50 pm
Forum: Algebra
Topic: The Trig Calculator
Replies: 1
Views: 627

### The Trig Calculator

A calculator is broken so that the only keys that still work are the $\sin$, $\cos$, and $\tan$ buttons, and their inverses (the $\arcsin$, $\arccos$, and $\arctan$ buttons). The display initially shows $0$. Given any positive rational number $q$, show that pressing some finite sequence of b...
Thu Aug 04, 2016 7:48 pm
Forum: Combinatorics
Topic: Tennis League (USAMO 1989)
Replies: 3
Views: 934

### Tennis League (USAMO 1989)

The 20 members of a local tennis club have scheduled exactly 14 two-person games among themselves, with each member playing in at least one game. Prove that within this schedule there must be a set of 6 games with 12 distinct players.
Thu Aug 04, 2016 7:29 pm
Forum: Social Lounge
Topic: Chat thread
Replies: 53
Views: 9316

### Re: Chat thread

Welcome, Zahin (and Raiyan)! Tell us, how did you guys get interested in math? And how do we use that info to force encourage new people to join?
Wed Aug 03, 2016 7:49 pm
Forum: Social Lounge
Topic: Chat thread
Replies: 53
Views: 9316

### Re: Chat thread

#make_BdMO_forum_great_again

We're gonna make a wall, and we'll get the bashers to pay for it!
Fri Jul 29, 2016 8:17 am
Forum: Social Lounge
Topic: Chat thread
Replies: 53
Views: 9316

### Chat thread

This is a thread to just talk about whatever you want! Let' try to make the forum a bit less dead, shall we?

To start, tell us who you are! I'm Zawad, from Chittagong. And right now I'm really confused why this awesome forum is so dead
Fri Jul 29, 2016 8:08 am
Forum: Social Lounge
Topic: A frequently asked question (FAQ)
Replies: 3
Views: 1569

### Re: A frequently asked question (FAQ)

Ragib Farhat Hasan wrote:
asif e elahi wrote:Of course. But set square is not allowed in IMO.
Is protractor allowed in IMO?
No, protractors are not allowed.
Sat Aug 29, 2015 6:07 pm
Forum: National Math Camp
Topic: Exam 2, Online Number Theory Camp, 2015
Replies: 24
Views: 5977

### Re: Exam 2, Online Number Theory Camp, 2015

Couldn't submit answers due to power failure :/ Can anyone give any tips on how to type out solutions faster?

btw, Vieta Jumping can direct you to the solution for number 4 but I didn't have to use it directly in the solution.
Fri Aug 28, 2015 3:56 pm
Forum: National Math Camp
Topic: Exam 2, Online Number Theory Camp, 2015
Replies: 24
Views: 5977

### Re: Exam 2, Online Number Theory Camp, 2015

ঘাত - কি Power বুঝাচ্ছে?
Sun Apr 26, 2015 4:56 pm
Forum: Introductions
Topic: O hai all!
Replies: 3
Views: 1678

### O hai all!

I solemnly swear that I'm up to no good
Tue Dec 03, 2013 9:24 pm
Forum: Combinatorics
Topic: Identity
Replies: 3
Views: 1718

### Re: Identity

Let $\color{red}{k}$ be the number of all students, $\color{red}{n}$ be the number of regional winners, $m$ be the number of national winners. We can choose regional winners from all participants in $\binom{n}{k}$ ways and national winners from regional winners in $\binom{k}{m}$ ways. Again we can ...