From CSE Blog
December 6, 2010 at 12:39 pm
Source: http://www.cut-the-knot.org/
Problem:
Assume a stick is broken at random into three pieces. What is the probability that the pieces can form a triangle?
Solve it in following cases:
Two ... (
more)
From CSE Blog
December 4, 2010 at 8:15 am
(Disclaimer: This post does not contain any puzzle, but it has sufficient math to keep you interested)
I saw Social Network three times in 1 week. Not for entertainment. Not ... (
more)
From CSE Blog
December 4, 2010 at 6:20 am
Source: Homepage of Tejaswi Navilarekallu, Post Doctoral Fellow, Vrije Universiteit, Amsterdam
Problem:
A professor decides the following grading scheme in his class. After ... (
more)
From CSE Blog
November 28, 2010 at 12:21 am
Source: Just made it up!
Problem:
Easy: Given 2 sorted arrays of size n, give an efficient algorithm to find the kth largest number.
Hard: Given m sorted arrays of size n each, ... (
more)
From CSE Blog
November 28, 2010 at 12:10 am
Source: Credit Suisse Placement Test at IITB
Problem:
You bet 1$ on a coin toss. A win gives u 1$ gain, a loss gives you a 1$ loss. The guy tossing the coin gets what he wants ... (
more)
From CSE Blog
November 12, 2010 at 1:59 am
You are trying to buy a stock at the best price. You need to buy it in the next 100 minutes. Every minute you will receive a random price (uniform
distribution) that is a number ... (
more)
From CSE Blog
October 30, 2010 at 2:45 am
Source: WQ Placement Test 2010 at IITB
Problem: You are given an urn with 100 balls (50 black and 50 white). You pick balls from urn one by one without replacements until all ... (
more)
From CSE Blog
October 29, 2010 at 8:04 pm
Source: WQ Placement Test 2010 at IITB
Problem: Consider a random walk around the edges of a square. From any vertex, the probability of moving to any adjacent vertex is 0.5. ... (
more)
From CSE Blog
October 23, 2010 at 4:28 am
Source: Asked to me by Nigel Coldwell (now posted on his blog)
Problem: Two creepers, one jasmine and other rose, are both climbing up and round a cylindrical tree trunk. jasmine ... (
more)
From CSE Blog
October 20, 2010 at 1:56 am
Source: Asked to me by Sudeep Kamath (Third year PhD Student, UC at Berkeley, EE IITB Alumnus)
Problem:
There are n men, n hats, one hat belonging to each person. A random permutation ... (
more)
From CSE Blog
October 18, 2010 at 11:27 am
Source: MIT OCW Course 6.041 / 6.431 Probabilistic Systems Analysis and Applied Probability
Problem:
Your Guests are all baseball fans and they wear baseball caps. There is a ... (
more)
From CSE Blog
October 16, 2010 at 5:00 pm
Source: William Wu Puzzle Page
Problem: Draw an equilateral triangle (all sides same length). Divide it into four identical shapes. remove the bottom left hand shape. now divide ... (
more)
From CSE Blog
October 14, 2010 at 3:03 am
Source: Asked to me by Sudeep Kamath (Third year PhD Student, UC at Berkeley, EE IITB Alumnus)
Problem: A box contains n balls coloured 1 to n. Each time you pick two balls from ... (
more)
From CSE Blog
October 10, 2010 at 1:20 pm
Source: Asked to me by Sai Teja Pratap (Sophomore Undergraduate, CSE, IITB)
Problem: There are 51 senators in a senate. The senate needs to be divided into n committees such ... (
more)
From CSE Blog
October 10, 2010 at 1:14 pm
Source: Asked to me by Vivek Jha (Senior Undergraduate, EE, IITB)
Problem: Among 10 given coins, some may be real and some may be fake. All real coins weigh the same. All fake ... (
more)
From CSE Blog
October 4, 2010 at 11:23 pm
Source: Wu William's Puzzle Page
Problem: A vendor is handing out free ice cream cones in alphabetical order of flavor, each cone being a different flavor. Kids are lined up at ... (
more)
From CSE Blog
September 22, 2010 at 4:02 pm
Disclaimer: Difficult Problem
Source: Amol Sahasrabudhe (Got his permission to put it on blog \m/ \m/)
Problem: Lets consider a two player game in which a number is given. The ... (
more)
From CSE Blog
September 9, 2010 at 6:04 am
Source: Puzzle Toad, CMU
Problem: Its raining outside and Alfonso and Bernadette are bored.
Alfonso suggests the following games:
(a) Two players alternatively erase some 9 ... (
more)
From CSE Blog
September 8, 2010 at 10:36 am
Source: Stanford Math Circle Sunday May 30, 2010
Problem: A circle is divided into 6 sectors. The numbers 1, 0, 1, 0, 0, 0 are written into the sectors in the counter clock-wise ... (
more)
From CSE Blog
August 27, 2010 at 7:09 am
Source: Asked by Amol
Problem:
An infinite checkerboard is divided by a horizontal line that extends indefinitely. Above the line are empty cells and below the line are an ... (
more)
From CSE Blog
August 21, 2010 at 7:05 am
Source: CMU Puzzle Toad
Problem: The wizards at Wall Street are up to it again. The Silverbags investment bank has invented the following machine. The machine consists of 6 boxes ... (
more)
From CSE Blog
August 20, 2010 at 6:46 am
Problem:
A man has two children. He says one of them is a son. What is the probability that the other one is also a son? (Hint: Answer is not 0.5 :P)
I have read this problem ... (
more)
From CSE Blog
August 18, 2010 at 9:16 am
Source: Saurabh Joshi's Blog
Problem: (copy-pasting from the source)
Suppose we have 13 cards arranged in descending order: K Q J 10 9 8 7 6 5 4 3 2 1
At any move, you can take ... (
more)
From CSE Blog
August 13, 2010 at 2:14 am
I keep rolling an unbiased die and adding up the sums till it exceeds 100. Once it does, I stop and record that final sum and call it X.
But at the beginning of the game you need ... (
more)
From CSE Blog
July 28, 2010 at 1:16 am
Source: Tanya Khovanova’s Math Blog
Problem: The Sultan decided to test the wisdom of his wizards. He collected them together and gave them a task. Tomorrow at noon he will ... (
more)
Loading ...