Problem Ten: Tricky Summation
Posted in Miscellaneous on September 30th, 2006 2 Comments »
Ok, last problem for today. This is a tricky one:
By moving one of the following digits, make the sum correct. 62 - 63 = 1
Update: Solutions have been posted!
Archive for September, 2006
Problem Nine: Two Unfortunate Men
Posted in Stupid on September 30th, 2006 4 Comments »
In a small cabin in the middle of the woods, two men lay dead. The cabin itself is not burned, but the trees around it is burned to ashes. How did these men die?
Update: Solutions have been posted!
Problem Eight: Bad Bird, Bad Bird!
Posted in Miscellaneous on September 30th, 2006 No Comments »
Here’s another interesting brain teaser I found on the Internet. It actually has some practical implications in technology.
An 18-wheeler is crossing a 4 kilometer bridge that can only support 10,000 kilograms and that’s exactly how much the rig weighs. Halfway across the bridge a 30 gram sparrow lands on the cab, but the bridge doesn’t collapse. Why not?
Update: Solutions have been posted!
Problem Seven: The Amazing Camel Race
Posted in Classic on September 30th, 2006 No Comments »
An old Egyptian Sheik summons his two sons to his death bed. According to tradition, only one of the two sons can inherit his father’s estate.
The two men will have to compete in a very unique camel race. Strangely though, the father will bequeath his fortune to the son whose camel crosses the finish line last.
Undecided as to how to begin the race because they have not solved their father’s riddle, the two brothers seek the advice of a wise man. No sooner have the two sons explained their predicament to the wise man, that they make a hurried dash for the waiting camels. What could the wise man have possibly told the sons for them to have scrambled to start the race?
Update: Solutions have been posted!
Problem Six: Forty+Ten+Ten=?
Posted in Crytarithms, Mathematical on September 30th, 2006 1 Comment »
Here is another interesting ‘restore the equation’ type problem. It was first asked by a New York math prof Alan Wayne who published it in the 1947 August issue of American Mathematical Monthly.
FORTY
TEN
TEN
+)
_________
SIXTY
Ain't it clever?
(I had to put 0's in front of the TEN's to make the formatting work)
Update: Solutions have been posted!
Problem Five: USA+USSR=?
Posted in Mathematical on September 30th, 2006 1 Comment »
This puzzle originated in Vol. 8 of Fascinating World of Mathematical Sciences by the Indian mathematician J.N. Kapur.
Restore the following equation:
USA + USSR = PEACE
where each letter represents a digit (i.e. USA is a three-digit number)
Update: Solutions have been posted!
Problem Four: Newcomb’s Paradox
Posted in Paradox on September 30th, 2006 No Comments »
This paradox is named after its originator, William A. Newcomb, a theoretical physicist at the University of California’s Lawrence Livermore Laboratory.
There are two boxes on the table: one opaque and one transparent. The transparent box has a dollar bill in it. The opaque box is empty at the moment. You have two choices: take the opaque box only or take both boxes.
One hour later, both boxes are removed. A computer called the decision prediction machine predicts the choice you have made. From experiments, the machine has 99% chance of predicting you decision correctly.
If the prediction machine predicts that you will take the opaque box only, a thousand dollars will be put into the opaque box. On the other hand, if it predicts that you will take both boxes, the opaque box will be left empty.
The boxes are returned to the table and you pick the box(es). Note that you have 99% chance of getting $1000 by picking the opaque box only. On the other hand, you always get $1 more by taking both boxes, regardless of the contents in the opaque box. What choice would you make?
Update: Solutions have been posted!
Problem Three: Cutting the Cake
Posted in Mathematical on September 30th, 2006 No Comments »
How do you divide a square cake into nine triangular slices such that every angle in every triangle is less than 90 degrees? The triangular slices don’t have to be of the same size.
Update: Solutions have been posted!
Problem Two: Big and Tiny
Posted in Logical on September 30th, 2006 No Comments »
Three families A, B, and C all consist of dwarfs and giants. Each of the families has at least one and at most ten of each type, with the total numbers of dwarfs and giants being equal. The giants are much heavier than the dwarfs, each weighing the same whole number squared times the weight of a dwarf. Consequently, the families with the least and the most members have an equal total weight.
Problem One: The Martians’ Apartment
Posted in Logical on September 30th, 2006 1 Comment »
The cities of Martians are small and crowded. Because of this limited space, the Martians live in multiple level high rise buildings. Six Martians, Albert, Bel, Carol, Danny, Erika, and Fido, each occupy a different floor in a six-story building.
When asked, the Martians claimed the following:
1. Albert does not live above the third floor;
2. Neither Carol nor Erika lives above Danny or Fido;
3. Fido does not live below Albert or Bel, and does not live above Danny;
4. Erika does not live below Bel or above Albert.
Who lives on which level?
Update: Solutions have been posted!
Solutions to Problems on Sept 27th, 2006
Posted in Solutions on September 30th, 2006 No Comments »
Answer One: A Secret Box
Original Problem
Answer Two: Seagull’s Crisis
Original Problem
Answer Three: The Escape
Original Problem
Answer Four: The Mystery Sequence
Original Problem
Answer Five: Who Are We?
Original Problem
Answer Six: The Line
Original Problem
Answer Seven: Critical Moment
Original Problem
Answer Eight: Buckets of Water
Original Problem
Answer Nine: Einstein’s Puzzle
Original Problem
Answer Ten: The Fifteen Game
Original Problem
Problem Ten: The Game of Know
Posted in Miscellaneous on September 29th, 2006 1 Comment »
Explain the rule in the Game of Know, described below:
I know pizza but not hamburger. I know happiness but not sadness. I know Jill but not Jack. I know mice but not cats. I know English but not French. I don’t know red, blue, yellow or green - in fact, I don’t know colours at all.
I don’t know the rules to the game, but I do know its instructions.
Update: Solutions have been posted!
Problem Nine: Placing Queens
Posted in Classic on September 29th, 2006 3 Comments »
Place 8 queens on an 8 by 8 chess board such that no two queens are on the same line.
Update: Solutions have been posted!
Problem Eight: Pigeons
Posted in Stupid on September 29th, 2006 3 Comments »
Seven pigeons perched on a branch. A hunter shot and killed one. How many remained?
Update: Solutions have been posted!
Problem Seven: Urban Planning
Posted in Classic on September 29th, 2006 1 Comment »
There exist three houses that need connection via plumbing to water, gas and electricity. How can the three houses and the three amenities be placed and connected so that no pipe crosses another?
Update: Solutions have been posted!