Five friends escape from a city one after the other. Each of them uses a different vehicle to move to a different hiding place. Michael escapes second, and he doesn't have an employer. David escapes before the person who used a helicopter, but after the person who escaped by car. John hides at a friends's place. When John escapes, Nick has already left. The last person who escapes uses a segway. The person who hides at his brother's uses a helicopter to get there, and it's not Michael. The person who escapes by bike hides at a classmate's place. Sam escapes by bus. Where is David hiding? David is hiding At a classmate's place The quickest way to notice this is to notice Only three places are named, friend's brother's, and classmate's. David is not John, and he did not escape by helicopter. This leaves only classmate's place remaining. It can then be verified Classmate's place requires David to esca...
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For a 9 x 9 Sudoku puzzle with a unique solution: 1. What is the fewest possible number of shown squares with which the puzzle can be solved? 2. What is the greatest number of shown squares that can't be solved? 3. How would one determine the answers to the two questions? est 1. 17 2. 77 3. For 1, see Mathematicians Solve Minimum Sudoku Problem | MIT Technology Review . It wasn't easy. For 2, all you need are four empty squares that are the four corners of rectangle, where the rectangle goes across two boxes, and the missing numbers are two of one value and two of another. Then there are two solutions, so it can't be solved. (Note: for #2, I am assuming that you mean the puzzle can't be solved because there is more than one solution, not because there are no solutions, i.e. the puzzle is invalid. For the no solution case, the answer is arguably 81, since you can provide a filled-in puzzle that is simply wrong, and there...
Can you solve the green dot square logic puzzle? Many others found the correct answer (11), but no one seemed 100% certain there were not more squares to find. Because this is such a small puzzle, I decided to use a brute force approach to prove it. I found all (12 choose 4) = 495 possible ways of choosing four different dots. Then, for each quadrilateral, I counted the total number of unique side lengths. If that count was one (all sides equal), it might be a square. Sure enough, there were only 11 such squares. This is a screenshot of the NodeBox program I wrote to show the solutions: 9.6k Views · 113 Upvotes Upvote 113 Downvote Comment 1 Share Bob Durrant , Jobbing mathematician and puzzle fan. Answered Apr 7 I also see 11. Here’s an example of what each looks like - there are 2 like the large red square, 4 like the medium yellow square, and 5 like the small ...
Can you solve this IQ test puzzle from Mensa? The answer is 2. How I arrived at this answer in a few seconds: 1) I questioned: How are the inner numbers created? (To identify a specific pattern. To identify which numbers interrelate to form this specific pattern. I noticed the outer rim numbers of this triangle are 4 and 2; and the inner number of the next triangle - clockwise - is 6.) 2) I added the outer rim numbers (4 + 2) and got 6. 3) 6 is the inner number of the next triangle (clockwise). 4) I added that triangle's outer rim numbers (3 + 7) and got 10. 5) The correct pattern is identified. (Adding the 2 outer rim numbers will give the inner number of the next triangle - clockwise.) 6) Going clockwise, the last triangle contains the outer rim numbers 1 and 1. 1 + 1 = 2 2 is the answer. Note: Demystifying a specific type of Mensa Test question This question tests for inductive and deductive reasoning skills as well as f...
What are some unsolved problems in math which seem easy at first glance? Here's a good one that's slightly less well known: if 2 x 2 x and 3 x 3 x are both integers, must x x be an integer as well? (This is known to be the case if you also assume that 5 x 5 x is an integer, but that's an extremely difficult theorem.) Oh, and here's another: can you color the points of the plane in 4 colors so that no two points 1m apart have the same color? How about 5 colors? 6? (With 3, you definitely can't (cool puzzle). With 7, you definitely can (slightly less cool puzzle). Nobody knows what the minimum number of colors is). please share if you like it