BrainDen.com - Brain Teasers

# Anza Power

Members

79

12

2. ## Moving South and East

I saw this riddle before, and I implemented an HTML version of it: http://anzapower.webs.com/riddles/amoeba/game.html And actually it has already been posted:

4. ## Ken Ken 3

Question, can the digits repeat inside an L-shaped area? For example the 14+ be: 2 6 6 ??
5. ## brain puzzle

Or dump everything and have 0 in all of them
6. ## dice problem

Actually it's O(1). Your comment got me thinking, I couldn't say that it's in NP because there is no n in the problem, We have 130 as a starting point and we want to see if any of the binome(129,8) dice combinations have 120 different sum... Unless you are referring to the problem with "N-sided Dice", then yeah that's crazy exponential...
7. ## A boy is late for school

Is the arrival time continuous or discrete (whole minutes)? Can we assume the distribution is uniform? Continuous time is the interesting case so let's look at that with uniform distribution:
8. ## [0,1] to (0,1)

No other conditions, although if you want something really interesting try having a continuous function... Oh, that's even simpler than what I had in mind:

10. ## Pushing objects through holes in other objects

Question is why would I go around pushing cubes in holes that are in other cubes?
11. ## building a bridge

Well, except that we are given the river as is, with a fixed width and a bridge perpendicular to its flow. We do not know whether the line joining the cities lines up with the bridge - a very special case with a trivial solution. We also do not know that the cities are equidistant from the river - a fact that bears on bridge placement if is not parallel to the joining line. I'm curious to know the two different ways BMAD has to optimize the bridge placement. You might've misunderstood me a little bit, I should have detailed a bit more, let the river be of width 1 unit, align the axis such that the x axis is parallel with and centered the river, in other words the river would be the area -0.5<y<0.5, now "removing" the river means collapsing it and so every point that was below it now goes up by 0.5 units and every point above it goes doen 0.5 units...
12. ## [0,1] to (0,1)

No other conditions, although if you want something really interesting try having a continuous function...

14. ## Sharing a sandwhich

You mean show that for any shape there exists a direction such that if you slice through it you get two equal halves?
15. ## [0,1] to (0,1)

Find a one-to-one and on mapping from the closed segment [0,1] to the open segment (0,1).
16. ## Ken Ken

There is lots of these and others on http://www.conceptispuzzles.com/ (Ken Ken is called CalcuDoku there)

18. ## Mensa Math/Logic Problems...How to Solve?

So many, don't have the energy to go through them all... The "find the missing number" type of questions don't usually have a strategy, you just stare at them and try to draw connections, look for patterns like for example are the numbers rising or falling, usually the answer should be very simple like taking a number and summing it's two digits and stuff like that.

20. ## dice problem

There is no mistake, 84 is the maximum for 7 sides, 120 is the maximum for 8 sides... In general, (n)*(n+1)*(n+2)/6 is the maximum for n sides.

23. ## Making a fair choice

Aha, ok then here's another idea:
24. ## Making a fair choice

There are many ways, not sure which one you are looking for.
25. ## Sudokurubikcube

^ the third row of the top square (the one with 9 7 6 6) is that intentional?
×

• #### Activity

• Riddles
×
• Create New...