Starting from this position, can you make 39 consecutive checks – 20 from White and 19 from Black?
The sequence is as follows:
1. Nh2+ f1N+
2. Rxf1+ gxf1N+
3. Ngxf1+ Bg5+
4. Qxg5+ Bg2+
5. Nf3+ exf3+
6. Kd3+ Nc5+
7. Qxc5+ Re3+
8. Nxe3+ c1N+
9. Qxc1+ d1Q+
10. Qxd1+ e1N+
11. Qxe1+ Bf1+
12. Nxf1+ f2+
13. Ne3+ f1Q+
14. Qxf1+ Qxf1+
15. Nxf1+ Re3+
16. Nxe3+ b1Q+
17. Rxb1+ axb1Q+
18. Nc2+ Nf2+
19. Bxf2+
NASA locates a meteor in outer space and concludes that it has either a cubical or spherical shape. In order to determine the exact shape, NASA lands a spacecraft on the meteor and lets a rover travel from the spacecraft to the opposite point on the planet. By measuring the relative position of the rover with respect to the spacecraft throughout its travel on the planet (in 3D coordinates), can NASA always determine the shape, no matter the route taken by the rover?
The answer is NO.
The question is equivalent to analyzing the intersection of a cube and a sphere which share a common center. Thus the question gets reduced to figuring out whether such intersection, which is a curve, can connect two opposite points on the sphere/cube.
Let the edge of the cube has length 1. If you pick the radius of the sphere equal to √2/2, the intersection will consist of 6 circles inscribed in the sides of the cube. Then the rover can just move along these circles from one point to its opposite and NASA won’t be able to figure out the exact shape.
Remark: It is not hard to see that 2:√2 is the only edge-radius ratio, for which NASA can’t figure out the shape.
The key to this riddle is only for you
Below are instructions, above this the clue
First strike the one near the head of a year
Then remove he who begins a cheer
Next take away the end of a tunnel
Then let us go to solve this puzzle
What you first took you must now take again
With three you are left, but fret not dear friend
Fattest to front and thinnest to rear
Add in two “eyes” and all becomes clear
Remark: The instructions in this riddle are quite literal.
The answer is XVIII, or 18 in Roman numerals.
The key is “only for you” – EXCLUSIVE. Remove “the one near the head of a year” – E. Remove “he who begins a cheer” – C. Remove “the end of the tunnel” – L. Remove “us” – U and S. Remove again E. Now you are left with X, I, V. Arrange them “fattest to front and thinnest to rear” – X > V > I. Add “two ‘eyes'” – I and I, so you get XVIII=18.
You are given 4 identical glasses, completely filled with transparent, odorless liquids. Three of the liquids are pure water, and the fourth is poison, which is slightly heavier. If the water glasses weigh 250 grams each, and the poisoned glass weighs 260 grams, how can you figure out which one is which, using a measuring scale just once?
Empty the first glass, fill around 1/4th of it with liquid from the second glass, and the rest 3/4ths with liquid from the third glass. Then, measure the first and fourth glasses simultaneously. If their total weight is:
– 500 grams -> the first glass is (was) the poisoned one
– between 500 and 505 grams -> the second glass is the poisoned one
– between 505 and 510 grams -> the third glass is the poisoned one
– 510 grams -> the fourth glass is the poisoned one
Four friends are trying to cross a bridge in complete darkness, but have only one flashlight. They need respectively 1, 2, 7, and 10 minutes to cross the bridge, and if any three of them step on the bridge at the same time, it will collapse. How many minutes do they need at least in order
They need 17 minutes. Label the friends A (1min), B (2min), C (7min), D (10min). A and B cross the bridge, then A returns back with the flashlight. C and D cross the bridge, then B returns back with the flashlight. Finally, A and B cross the bridge.
In order to see that this is optimal, notice that when D crosses, he needs at least 10 minutes. If C crosses separately, this will make already 17 minutes in total. Therefore C and D must cross together, and A and B must be at that time on the two opposite sides of the bridge. From here it is easy to conclude that the friends indeed need at least 17 minutes.
On which spot was the white queen captured?
Since the pawns on e6 and h6 have taken 2 of the White’s pieces, and the only two white pieces which could get there are the knight and the queen, the answer is one of these two squares. Similarly, the pawn on b3 should have taken the Black’s c8 bishop, and this should have happened before the White’s queen was taken. Therefore first the white knight was taken on e6, then the black bishop on b3, and finally the white queen on h6.
Find your way through the pipes from START to FINISH.
The solution is shown below.
Your grandma’s wall clock chimes the appropriate number of times at every whole hour, and also once every 15 minutes. If you hear the wall clock chime once, how much more time do you need to figure out what the time is, without looking at it?
1 hour and 30 minutes. The wall clock will chime once at 12:15, 12:30, 12:45, 1:00, 1:15, 1:30, 1:45. If you hear 7 consecutive times just 1 chime, then the time is 1:45. If you hear less than that, you will easily find what the time is once again.
If you have one match and enter a room in which there is a stove, a kerosine lamp, and an oil burner, what will you light up first?
The match.
Please confirm you want to block this member.
You will no longer be able to:
Please allow a few minutes for this process to complete.
