All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info
Home
Welcome to perplexus.info, flooble's perplexing puzzle portal. Here, we collect all sorts of puzzles, from simple logic questions and word tricks to in-depth math problems like probability and geometry. Click around and see if your brain is up to the task! If you're new here, make sure you sign up so that you can leave comments and submit your own problems!
> Logic> Probability> Shapes> General (1)
> Numbers> Games> Paradoxes> Riddles
> Just Math (5)> Science> Algorithms
⌈1  0⌉⌈x⌉=⌈ x⌉
⌊0 -1⌋⌊y⌋=⌊-y⌋

The above 2x2 matrix reflects a point over the x-axis. (x,y)→(x,-y).

Derive a matrix that will reflect a point over the line y=kx.

(No Solution Yet, 1 Comments) Submitted on 2015-04-01 by Jer   
Difficulty: 2 of 5 Bonus: Mr and Mrs Brown (in Logic) Rating: 2.86
Mr and Mrs Brown are a little strange. When they are awake, their judgement about everything is absolutely perfect. When they are asleep however, it is exactly the opposite.

That is, if Mr Brown is awake and thinks that something is true, then it will always be true. But if he were to be sleeping and dreaming something to be true, it would always turn out to be false.

Once, late at night, Mr Brown was under the impression that Mrs Brown is asleep. At that very point in time, Mrs Brown was also thinking about her husband. Was she under the impression that he was asleep or that he was awake?

(Solution Posted, 9 Comments) Submitted on 2002-04-26 by levik   
Difficulty: 1 of 5The Red Rows (in Tricks)
Posted on 2015-04-01 by K Sengupta (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Function Function Function Function Foray (in Just Math)
Posted on 2015-03-31 by K Sengupta (No Solution Yet, 2 Comments)
Difficulty: 2 of 527-8=19 (in Just Math)
Posted on 2015-03-31 by Ady TZIDON (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Nine times SSD (in Just Math)
Posted on 2015-03-30 by K Sengupta (No Solution Yet, 1 Comments)
Difficulty: 2 of 5How many solutions? (in Just Math)
Posted on 2015-03-30 by Ady TZIDON (No Solution Yet, 1 Comments)
Difficulty: 3 of 5Power Equality Poser (in Just Math) Rating: 3.00
Posted on 2015-03-29 by K Sengupta (No Solution Yet, 4 Comments)
Difficulty: 3 of 5Distinct Solution Decision (in Just Math)
Posted on 2015-03-28 by K Sengupta (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Oxymora galore (in Word Problems) Rating: 5.00
Posted on 2015-03-27 by Ady TZIDON (No Solution Yet, 1 Comments)
Difficulty: 3 of 5Animal to animal (in Word Problems)
Posted on 2015-03-27 by Ady TZIDON (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Neighboring tickets (in Numbers)
Posted on 2015-03-26 by Ady TZIDON (No Solution Yet, 2 Comments)
Difficulty: 2 of 5Island Adventure (in Liars and Knights)
Posted on 2015-03-26 by Math Man (No Solution Yet, 1 Comments)
Difficulty: 3 of 5Zero Sum Expression (in Just Math)
Posted on 2015-03-25 by K Sengupta (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Win some, lose some II (in Just Math)
Posted on 2015-03-25 by Ady TZIDON (No Solution Yet, 1 Comments)
Difficulty: 3 of 5Long list (in Word Problems)
Posted on 2015-03-24 by Ady TZIDON (No Solution Yet, 2 Comments)

Recently Posted Solutions:
Difficulty: 4 of 5Chord Triangle Constant (in Geometry)
Submitted By Bractals. Solution posted on 2015-03-30 13:21:15
Difficulty: 1 of 5Keys and boxes (in Logic)
Submitted By Math Man. Solution posted on 2015-03-22 07:42:00
Difficulty: 4 of 5My travel IN SOME ORDER (in Numbers)
Submitted By Ady TZIDON. Solution posted on 2015-03-17 14:25:39
Difficulty: 4 of 5A cryptic toast (in Cryptography)
Submitted By Ady TZIDON. Solution posted on 2015-03-16 06:51:16
Difficulty: 3 of 5Academia, defeated, yesterday (in Word Problems)
Submitted By Ady TZIDON. Solution posted on 2015-03-08 10:24:55
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (5)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2015 by Animus Pactum Consulting. All rights reserved. Privacy Information