Puzzle Definition and 618 Threads

  1. M

    How Many Aliens? Solve the Puzzle!

    u have a certasin number of aliens in a room they each have the same number of hands and fingers ,,the total number of fingers in the room is just under 300...clue is that there is an answer with logic behind it. question how many aliens were there? (a specific number)
  2. S

    Brain-Teasing Tattoo Puzzle: Find the Date

    Ok, I know this is not too much of a teaser but maybe you guys could come up with something cool and original. I'm getting a tattoo and part of it has my birthdate in it. Except I don't want it to be obvious...I want some type of complicated equation with lots of mathmatical symbols etc so if...
  3. K

    Solving the Ladybug's Clock Puzzle: Unraveling the Mystery

    Ok here is what the problem states in the book "A ladybug settled onto the tip of a clock's minute hand. The minute hand is 12ft long. How far does the ladybug travel from 3:00pm to 3:20pm?" I figured there are 30 degrees to every hour (divide 360 by 12). Then the 20 minutes would...
  4. B

    Solving a T-Shaped Tube Puzzle: What Happens When Air Is Blown?

    Well, i have been doing some fluids problems, and i came upon this. It has me stuck A T-shaped tube with a constriction is inserted in a vessel containing a liquid. What happens if air is blown through the tub from the left? A) The liquid level in the tube rises above the surface of the...
  5. MathematicalPhysicist

    Ancient puzzle, solved by abstract algebra?

    i reackon youv'e seen it already, the problem is to rearrange the next numbers in the fixed order: 1 2 3 4 5 6 7 8 9 11 10 when you have at the last entry a vacant place you need to put it in order. this is from the text of edwin h. connell, and i think it's impossible (after a lot...
  6. Chi Meson

    Planarity Puzzle - Test Your Puzzle-Solving Skills!

    Just in case you have some time that isn't yet wasted. Has anyone else tried this puzzle? I took just over 20 minutes to do level 12, then it seems to get exponentially more difficult. It's much more fun replaying level 10 or 11. http://www.planarity.net Every now and then you find a...
  7. H

    Solve the Puzzle: Find the Odd Coin in 3 Weighings

    You have twelve coins, eleven identical and one different. You do not know whether the "odd" coin is lighter or heavier than the others. Someone gives you a balance and three chances to use it. The question is: How can you make just three weighings on the balance and find out not only which coin...
  8. TheStatutoryApe

    Poker Chip Puzzle: Jim's Deduction Explained

    There is a full story that comes along with this puzzle but I will just stick to the puzzle itself. There are four men. Three of them are friends and the fourth has approached them with a proposition for a bet which they have taken him up on. We'll call the three friends Bob, Tom, and Jim...
  9. J

    Solve the Meal Costing Puzzle: Calculate Food Costs for 120000 Meals

    Hi, please help me with this. Find the cost per meal if you serve 120000 meals, spend $46000 in food purchases and $1250 worth of food was removed from the inventory. How should i proceed with this problem. Please let me know,thanks.
  10. T

    Can You Solve This Challenging Puzzle from HighIQSociety.org?

    this is a puzzle from highiqsociety.org i've been looking at this for a very long time, can anyone break this? http://www.geocities.com/invinbotmail1/hd3
  11. P

    Solve Gravity Puzzle: m1 & m2 Connected by a Bar

    Imagine that we have two masses m1 & m2 connected by a "rigid" but lightweight bar. The masses are attracting each other in essentially a Newtonian way (the masses are not so large as to need GR to calculate the force). Picture: m1 | |<... bar of length d, cross sectional area A |...
  12. M

    What is the significance of the numerical sequence 11111121113122223222?

    from a website I've seen wat does this sequence represent- 11111121113122223222 enjoy
  13. M

    Will the Last Ball Always Be the Same Color in This Brainteaser?

    posting my 1st brainteaser ...hopefully u might enjoy uve got 20 blue balls and 14 red balls all mixed up ( u also have some spare balls outside the box) in a box u have to take out 2 balls at a time. if they r the same leave them outside of the box and put in a blue spare (the spares r not...
  14. J

    Solving Water Level Puzzle: Page 6 of 1902 Exam Solutions 2004

    Please refer to page 6 of http://www.physics.usyd.edu.au/ugrad/jphys/jphys_webct/jp_exams/1902_exam_2004.pdf I'm quoting from the solution guide: http://www.physics.usyd.edu.au/ugrad/jphys/jphys_webct/jp_exams/1902_exam_solutions_2004.pdf P_1 = P_A + \rho g y_1 and P_2 = P_A +...
  15. M

    Solving the Sheep and Grass Puzzle: Maximum Number of Sheep

    I got this question from my teacher to be completed by the beginning of Dec. It goes like this. sheep eat grass at a fixed rate grass grows at a fixed rate 1 sheep in a pen eats grass forever 8 sheep eat grass in 5 days then starve 9 sheep eat grass in 4 days then starve I figure...
  16. S

    Solving a Spring Compression Puzzle: Work Done by Gravity

    Spring Question! A 250g block is dropped onto a relaxed vertical spring that has a spring constant of 2.5N/cm. The block becomes attached to the spring compresses the spring 12 cm before momentarily stoppoing. While the spring is being compressed, what work is done on the block by (a)The...
  17. F

    Solving Physics Puzzle: Prove Guy Slides off Ice Mount at 2/3R Height

    Hi, I encountered this problem while I was studying for a Physics test, and this is how far I got, hopefully someone can point me in the RIIGHT direction. The proof goes like this, a guy is sitting on the top of an ice hemisphere, and someone pushes him off, and so he slides down the...
  18. G

    Why Do Handshake Numbers at a Party Always Pair Highest with Lowest?

    I've come up with a partial solution (a correct answer in fact) to this puzzle but am not completely satisfied in that I don't fully see how it works. the problem is: I and my wife invite 10 couples to a party. At the end I ask everyone except for myself how many people they have shaken hands...
  19. I

    Solve the Puzzle: Find the Scale Readings for a Mass Distribution

    formula Help! i got this question but i don;t know which formula to use Q - A 1m plank of Mass 1.0kg is placed on two scales which are at either end of the plank. Masses are hung underneath the plank. Mass A = 5.0kg at a distance of 0.30m from the left of the plank Mass B = 5.0kg at a...
  20. F

    Solving the Puzzle: Calculating Watts of "Wonderland's Watt

    hi, i have another question i can't get, the problem is: We want to boil one liter of water in a light thin-walled vessel. For this purpose, we start to heat water by an electric heater, with the label "500W. Made in Wonderland". However, after the temperature becomes 60*C, it stops...
  21. Math Is Hard

    What Are These Abbreviations For Familiar Quantities?

    This is a fun little puzzle a friend sent me a while back. It's all abbreviations for recognizable quantities of things, for instance, # 0 is 24 hours in a day. At one point my friend and I worked them all out but there's a few I may have forgotten. Anyway, I thought you might enjoy these...
  22. JasonJo

    Can You Beat the Odds in This Probability Challenge?

    I know two distinct secret numbers: call them X and Y, and assume that X < Y, without loss of generality. You have no clue how I came up with them. They could be anything (positive, negative, rational, irrational, etc). They could come from any probability distribution (discrete or continuous)...
  23. I

    Solving the Water-Lifting Puzzle: An Analysis of Efficiency and Output

    A farmer uses a pump to lift water from a river to a arable land who lies 5.0m higher than the river. The pump exhaust an electrical effect of 1.0kW but only 65% is used to do the lifting. ok A) I have resolved the lifting work is 0,65*60 = 39kJ But B) is harder,,,, how much water is pumped...
  24. G

    Interesting puzzle involving prediction/preemption

    I came across this puzzle a while ago and recently recalled it but couldn't come up with any solid solution/explanation. What are your thoughts? I want to choose one day, in a five day window (we'll say monday to friday), on which an event will occur. (For simplicity of interpretation and...
  25. M

    Solving a Photographic Puzzle: Comparing Heights of Images at Varying Distances

    hey, i tried the following problem and i think i got it wrong well. here is the problem and what i did. problem A photograph of a zebra is taken from a distance of 100m with a 50mm lens. A second picture is taken from a distance of 50m with the same lens. What is the ratio of the height of...
  26. I

    Calculating Attraction Between Cokes: Solve the Puzzle

    I don't know how to do this, 2 Cokes standing 35 cm from each other, Calculate the attraction to each other. One can weights 365grams. Ok I know we should use G*m1m2/r1 and I have tried that and the result becomes only wrong like this 0,365*0,365 / 0,35 =0,3806428571 * 6,67*10^-11...
  27. S

    Solving the Speedster Puzzle: Calculating Time to Catch Up

    I am stuck on this problem... A speeding motorist traveling 120 km/h passes a stationary police officer. The officer immediately begins pursuit at a constant acceleration of 10.2 km/h/s (note the mixed units). How much time will it take for the police officer to reach the speeder, assuming that...
  28. R

    Label Puzzle: Determine Bead Contents

    In one container there are two black beads, in another two white beads, and in a third there are one black and one white bead. They are labelled appropriately BB, WW, and BW. Someone moved the labels in such a way that for each container the label doesn't show its contents. Can you determine the...
  29. P

    Solving the Puzzle: Acceleration of a 50kg Block

    I'm not sure why I'm not getting this problem right. It seems pretty simple to me, but I guess there might be a trick to it? Suppose that a 50kg block slides along a horizontal surface where the coefficient of kinetic friction between the block and the surface is uk = 0.60. A force F = 400 N...
  30. DaveC426913

    Unlock the Geometry Puzzle: Minimum Pictures Needed

    A geometry puzzle: Say I want to obtain an image of an object (eg. a toy car) from every possible angle in 3-dimensions, in, say, 15 degree increments. How many pictures would I need to take? The immediate answer is 576. 1] Rotate the car around X axis through 360 degrees in 15 degree...
  31. T

    Solving System of ODEs: A Puzzle

    In order to solve this pde that I'm on, I must solve this system of odes, \frac{dx}{dt} = -y and \frac{dy}{dt} = x , which doesn't look bad, but I haven't had a second semester of ode yet where systems of differential equations are covered. How is this solved?
  32. C

    What is the solution to the MI string puzzle?

    I don't know if you have encountered this problem in Logic and Mathematics. Anyway, you may try this: You are given with an initial string of MI. Here are the rules: i) If you have a string that ends with I you can add a U ii) If you have an Mx, (i.e., an a string that starts with...
  33. T

    Can anyone solve this shape of a string puzzle?

    Can anyone solve this... "shape of a string" puzzle? Let's say there is an infinite massless and elastic string, which laid horizontally and one of the ends is extended to infinite distance. The string is "pulled" thoroughly and somehow, so that there is a tension T along it. There is a...
  34. E

    Brain-Teasing Puzzle for Engineering Majors

    Hello everyone, I was wondering if you could advise me a good puzzle I could give to my engineering-major friends, something tough that they would break their brains on :devil:. I was thinking of petals around the rose. Any other suggestions are very much welcome!
  35. Y

    Solve the Exciting Math Puzzle: 1-9, No Repetition!

    Heres an exciting number puzzle that i got from a friend of mine: >> make a combination of any of the four basic math operations (+,-,x or /) such that numbers from 1-9 is visible without repeatition. ex. 2x3=6+1=7 note: it is not necessary that the four operations could be used...
  36. A

    Can You Solve the Four Nines Puzzle?

    Hi! I have a puzzle here and was wondering if you guys could solve it. Using exactly four nines each time and no other numbers or letters, find expressions which evaluate to every integer between 0 and 132. You may put parentheses wherever you wish and uses whatever mathematical symbols...
  37. S

    What is the reworded formula for Fermat's last theorem?

    I am thinking of a famous formula related to number theory, but I have reworded it (this may not be original to me -- I don't know). Can you name the theorm: If a, b, c and n are positive integers, then a^{n}=\int_{b}^{c}n{x^{n-1}}dx has no solutions for any n > 2 . Maybe we can...
  38. D

    The Plasmid Puzzle: Exploring the Role and Evolution of Plasmids in Bacteria

    I’m a little bit confused with plasmids. I understand how they work replicate and function, but I can't say why do they exist ? What is plasmid role, what is so special they do so they are worthy of existence? Almost every plasmid feature is “supported” by bacterial chromosome. Why when and...
  39. K

    Solve the A4 Sheet Folding Puzzle!

    In year 12 my maths teacher gave the class this puzzle. The idea is to fold an A4 sheet of paper, along the lines, such that the numbers are in order. Just to make it clear, the numbers don't have to be in order as you unfold it or anything, but when folded the rectangle of paper directly...
  40. P

    The hardest logical puzzle according to George Boolos

    According to the late philosopher and logician George Boolos, who was a professor at MIT, the hardest logical puzzle is one that was invented by the logician and puzzle-master Raymond Smullyan, and modified slightly by the computer scientist John McCarthy. Here is the puzzle : :cool:
  41. mattmns

    Minesweeper Puzzle: A New Challenge

    Not as interesting as the other, but I had never seen it before, until I lost to it a while ago :smile: Mainly looking at the left center. http://img280.echo.cx/img280/46/minesweepertest5ax.gif
  42. J

    Four Fours Puzzle: Get Each Integer with 4s

    This one is just for fun, I do not have the answer myself. I was reminded of it by BicycleTree's procedure. The goal is to get each integer as the result of using any of the four operations, and exponentiation, operating on four fours. For instance: 1 = 4 - 4 + 4/4 2 = 4/4 + 4/4 3 = (4 + 4...
  43. G

    Is This Minesweeper Grid Solvable Without Guessing?

    Saw this at a website.. [] [][][][] [] [] 2 2 2 2 [] [] 2 0 0 2 [] [] 2 0 0 2 [] [] 2 2 2 2 [] [] [][][][] [] See if you can figure it out without guessing and checking (derive the solution logically). Might be easier for minesweeper addicts. edit, darn the spacing is...
  44. B

    Can a line be constructed that ends in any positive integer whatsoever?

    I had this idea this morning and was going to make another "figure-out-the-sequence" out of it, until it occurred to me that it was slightly more interesting than that. Consider the following procedure: start a line with 0 2, and add on additional numbers as you please so long as the...
  45. Z

    How can you identify a defective machine with only one use of a scale?

    I am sure this one has been done a million times, but I can't figure this out. It about 10 mint producing machine and one of them is defective and produces coins that weigh 10% less than the other 9. You have a scale but you can only use it once and only once, how would you identify the...
  46. T

    Solving Puzzle of Limit of Integral: $\frac{2e^{-i\alpha x}}{1+\alpha^2}$?

    This isn't really homework for a class, but i figured this would be the most appropriate place for this question: What would this quantity be? \lim_{t \rightarrow \infty} e^{-i \alpha |x - t|} \cdot (|x -t| - 1) - \lim_{t \rightarrow - \infty} e^{-i \alpha |x - t|} \cdot (|x -t| - 1) = ...
  47. Andre

    Solve Bridge Puzzle: South Makes 6 NT

    Can I amuse anybody with a bridge puzzle? I made it some 25 years ago and it took almost a year to debug it. So if you find the solution within minutes then that’s either brilliant or you found one of the two build-in traps. The real solution looks unusual. South plays six No Trump, west...
  48. J

    Solving the Math Department Puzzle Last Semester

    This was circulating about the math department last semester and I thought some of you might enjoy it. Good luck. The solution to the following puzzle is unique; in some cases the knowledge that the solution is unique may actually give you a short-cut to finding the answer to a particular...
  49. K

    Find the Answer to the Ball's Velocity Puzzle

    please help me! I will be so happy if someone gives the answer to this question in a while. A ping pong ball of radius R and mass M is started with an initial speed Vo and a backward initial angular velocity of wo.The coefficient of kinetic friction between the ball and the table is µk.What...
  50. B

    What Do You Get When You Multiply the Next Two Numbers in This Sequence?

    Can someone help me with this math puzzle? :confused: Can anyone figure this out? :confused: If you take the next two numbers in this sequence and multiply them together, what number will you get? 594, 487, 566, 493, 310, 447, ____, ____
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