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
> Numbers> Games> Paradoxes> Riddles
> Just Math (4)> Science> Algorithms
Determine the volume generated by the revolution of the conic

x = a cosθ and y = b sinθ

about the line x = 2a.

(No Solution Yet, 0 Comments) Submitted on 2025-04-25 by K Sengupta   
Difficulty: 3 of 5 Bonus: 10 cell phones and 10 numbers (in Probability) Rating: 4.25
You are given 10 cell phones and 10 cell numbers(each number corresponds to one of each of those 10 cell phones), but you don't know which number corresponds to which cell phone. Your task is to label each cell phone with its corresponding number. Using optimal procedures, what is the probability that you will finish the task in exactly 5 attempts?

A single attempt is defined as calling a number from a cell phone.

Hint: The caller's number will be displayed in the cell that is being called.

(Solution Posted, 11 Comments) Submitted on 2008-06-11 by Praneeth   
Difficulty: 3 of 5Function to inverse (in Calculus)
Posted on 2025-04-25 by K Sengupta (No Solution Yet, 0 Comments)
Difficulty: 3 of 5Boxed real number range (in Just Math)
Posted on 2025-04-24 by Danish Ahmed Khan (No Solution Yet, 3 Comments)
Difficulty: 2 of 5What is the value of F(6) (in Just Math)
Posted on 2025-04-24 by K Sengupta (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Rectangular distance problem (in Geometry)
Posted on 2025-04-23 by Danish Ahmed Khan (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Coin fitting (in Just Math)
Posted on 2025-04-23 by Danish Ahmed Khan (No Solution Yet, 5 Comments)
Difficulty: 2 of 5Divisible neither by 5 nor by 7 (in Numbers)
Posted on 2025-04-22 by K Sengupta (No Solution Yet, 1 Comments)
Difficulty: 3 of 5The maximized pentagon (in Geometry)
Posted on 2025-04-22 by Danish Ahmed Khan (No Solution Yet, 0 Comments)
Difficulty: 3 of 5The Math club (in Just Math)
Posted on 2025-04-21 by Danish Ahmed Khan (No Solution Yet, 5 Comments)
Difficulty: 3 of 5Golden polynomials (in Just Math)
Posted on 2025-04-21 by Danish Ahmed Khan (No Solution Yet, 1 Comments)
Difficulty: 2 of 5What is the value of F(101) (in Numbers) Rating: 3.00
Posted on 2025-04-20 by K Sengupta (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Determine the differential equation (in Calculus)
Posted on 2025-04-19 by K Sengupta (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Friedman number (in Numbers)
Posted on 2025-04-18 by Danish Ahmed Khan (No Solution Yet, 3 Comments)
Difficulty: 3 of 5Fermat’s Little Theorem (in Numbers)
Posted on 2025-04-18 by Danish Ahmed Khan (No Solution Yet, 2 Comments)
Difficulty: 3 of 5Pythagorean median (in Just Math)
Posted on 2025-04-17 by Danish Ahmed Khan (No Solution Yet, 1 Comments)

Recently Posted Solutions:
Difficulty: 3 of 5Recipropandigital (in Numbers)
Submitted By Larry. Solution posted on 2025-04-17 10:44:15
Difficulty: 3 of 5Troublemaking Sequence (in Sequences)
Submitted By Larry. Solution posted on 2025-04-15 13:24:44
Difficulty: 3 of 5Savings Bonds (in Algorithms)
Submitted By Charlie. Solution posted on 2025-04-02 18:52:29
Difficulty: 4 of 5The Happy Farmer (in Probability)
Submitted By Charlie. Solution posted on 2025-03-28 08:27:53
Difficulty: 3 of 5Play Time (in Logic)
Submitted By Charlie. Solution posted on 2025-03-13 08:43:05
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 (10)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2025 by Animus Pactum Consulting. All rights reserved. Privacy Information