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# jasen

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## Posts posted by jasen

1. ### Prove that you solved sudoku

after a week long journey abroad, now I'm active again.

@phil1882: The solution does not require a computer. I do not see well encrypting decrypting by hand.

All you need: scissors, paper, pencil.

After thinking again, and using the clue harrey give us (scisors, pen, and paper),

Yes it is possible to prove it without computer, but it takes many steps.

2. Put it with back side up on the floor, and ask your friend (who need prove) to numbering it. Better numbering it like (horz, vert) format
3. Cut it to smaller peaces, every squere (with a number) 1 peace.
4. Rearrange it with back side up, then turn over/show the numbers in question in the right place. (means you are not cheating)
5. now take all the squares in first row, suffle it, turn then over secreatly, and show them to your friend, that all number from 1 to 9 are there.
back to step 4 and do the same with other rows (vert and horz). and other 3x3 squares.

2. ### Left of center?

each number must be an unique number or not?

3. ### Prove that you solved sudoku

using computer program that check your solution.
then the computer check it and say right or wrong.

4. ### Random bullets

Suppose the leading bullet has 1/k chance of being the fastest.  Then we will not get complete annihilation.
So far, so good. ....

After rethinking this, I understand the doubter opinion.

We have to avoid using "first bullet fastest"
Although first bullet is not the fastest, it it still possible that the first bullet escape

1 4 2 3  -> in this arrangement  3 (first bullet) is not the fastest, but it escape.

-----

we better explain it in another way.

with n bullets, if the fastest bullet is not the first, there is (n-1)/n cases that we are sure there will be a collision. n-2 bullets will remains.  an so on...

5. ### Need directions

Mentally draw a line that connects the horns of a crescent moon and then extend this line down to the horizon. ........

OK, if there is crescent moon outside, this is one of the answers.

6. ### Random bullets

The interesting fact is : Whatever number of bullets fired, the highest probability is 2 bullets left.

initial  2 bullets  1000000 tries
P of 0 bullets anhilated =  .500683
P of 2 bullets anhilated =  .499317

initial  4 bullets  1000000 tries
P of 0 bullets anhilated =  .041601
P of 2 bullets anhilated =  .582647
P of 4 bullets anhilated =  .375752

initial  6 bullets  1000000 tries
P of 0 bullets anhilated =  .001354
P of 2 bullets anhilated =  .076568
P of 4 bullets anhilated =  .609111
P of 6 bullets anhilated =  .312967

initial  8 bullets  1000000 tries
P of 0 bullets anhilated =  .000029
P of 2 bullets anhilated =  .00346
P of 4 bullets anhilated =  .104317
P of 6 bullets anhilated =  .619309
P of 8 bullets anhilated =  .272885

initial  10 bullets  1000000 tries
P of 0 bullets anhilated =  0
P of 2 bullets anhilated =  .000075
P of 4 bullets anhilated =  .006025
P of 6 bullets anhilated =  .127299
P of 8 bullets anhilated =  .620703
P of 10 bullets anhilated =  .245898

initial  12 bullets  1000000 tries
P of 0 bullets anhilated =  0
P of 2 bullets anhilated =  .000002
P of 4 bullets anhilated =  .000186
P of 6 bullets anhilated =  .008569
P of 8 bullets anhilated =  .147078
P of 10 bullets anhilated =  .618606
P of 12 bullets anhilated =  .225559

initial  14 bullets  1000000 tries
P of 0 bullets anhilated =  0
P of 2 bullets anhilated =  0
P of 4 bullets anhilated =  .000002
P of 6 bullets anhilated =  .000258
P of 8 bullets anhilated =  .011055
P of 10 bullets anhilated =  .164173
P of 12 bullets anhilated =  .614903
P of 14 bullets anhilated =  .209609

initial  16 bullets  1000000 tries
P of 0 bullets anhilated =  0
P of 2 bullets anhilated =  0
P of 4 bullets anhilated =  0
P of 6 bullets anhilated =  .000008
P of 8 bullets anhilated =  .000366
P of 10 bullets anhilated =  .013871
P of 12 bullets anhilated =  .178564
P of 14 bullets anhilated =  .610811
P of 16 bullets anhilated =  .19638

initial  18 bullets  1000000 tries
P of 0 bullets anhilated =  0
P of 2 bullets anhilated =  0
P of 4 bullets anhilated =  0
P of 6 bullets anhilated =  0
P of 8 bullets anhilated =  .000005
P of 10 bullets anhilated =  .000545
P of 12 bullets anhilated =  .016474
P of 14 bullets anhilated =  .191395
P of 16 bullets anhilated =  .606078
P of 18 bullets anhilated =  .185503

initial  20 bullets  1000000 tries
P of 0 bullets anhilated =  0
P of 2 bullets anhilated =  0
P of 4 bullets anhilated =  0
P of 6 bullets anhilated =  0
P of 8 bullets anhilated =  .000001
P of 10 bullets anhilated =  .000012
P of 12 bullets anhilated =  .000665
P of 14 bullets anhilated =  .018998
P of 16 bullets anhilated =  .203064
P of 18 bullets anhilated =  .601149
P of 20 bullets anhilated =  .176111

7. ### Couple of sequences

Of cards - Uncover the three next elements of the following sequence: 8593,8600,8593,8592,8599,...

8593, 8600, 8593, 8592, 8599, 8593, 8591, 8598

8. ### Number

1111111110000

since 720 * 1543209875 = 1111111110000

9. ### Need directions

Hidden Content

Hidden Content

Right !

You can create a compass from a battery, copper coil, a nail, and thread.

1. take a battery, and coils from the clock.
2. take a nail from wall. (to hang a clock, we need a nail).
4. create magnet. http://www.wikihow.com/Create-a-Magnet-With-a-Wire-and-a-Nail
5. using right hand rule to find south and east. https://en.wikipedia.org/wiki/Right-hand_rule
6. Find center ballance, and hang the magnet using thread.

now you know direction.

11. ### Marathon (mini) puzzles (trapped in a dungeon)

Hidden Content

Right

You can create a compass from a battery, copper coil, a nail, and thread.

1. take a battery, and coils from the clock.
2. take a nail from wall. (to hang a clock, we need a nail).
4. create magnet. http://www.wikihow.com/Create-a-Magnet-With-a-Wire-and-a-Nail
5. using right hand rule to find south and north. https://en.wikipedia.org/wiki/Right-hand_rule
6. Find center ballance, and hang the magnet using thread.

now you know direction.

12. ### Number

1110101111010000

since 1110101111010000 / 720 = 1541807098625

13. ### Need directions

Doesnt Sun consider as  a star?

Well, it's nighttime, so you shouldn't see the Sun.
The Sun is a star indeed, and it didn't occur to me the moon is not a star. Supposedly you could deduce the cardinals from the hour and the moon position?

In the night you can't use sun as guidance.

Unfortunately no astronomer between the prisoners,
nobody could deduce the cardinals from the hour and the moon position.
You see arround, wheather there are tools you can use.
But you only can find electric lamp, hanging photo, and the working clock.

1st clue : use component from the clock.

14. ### small vs large

First player will always choose a biggest number and put (-) in front
Second player will always choose a biggest number and put (+) in front

so the result will be

-20+19-18+17-16+15-14+13-12+11-10+9-8+7-6+5-4+3-2+1 = -10

15. ### Need directions

you are a prisoner in a huge jail. All prisoner will be executed in the morning next day. Fortunately No guard there. Suddenly in midnight a prisoner can break his cell. and take all keys. But he will not free and let others escape with him, except there is someone can tell  directions (south, east, north or west), because wrong directions means recaptured. Nobody can read star for directions. You see a clock on the wall ticking, and your execution time get closer.

What should you do to know the right direction?

16. ### love in kleptopia

Should be:

Hidden Content

This is a subject in cryptography

A don't want to send his key to B.
B also don't want to send his key to A.
But they want to communicate in insecure Internet connection.
So they have to use an encryption method which work like this.
Only commutative encryption method can answer this problem.

17. ### 100 white marbles

P(1 Black) = 0.99 100
P(2 Black) = 0.98 100
P(3 Black) = 0.97 100
P(4 Black) = 0.96 100
P(5 Black) = 0.95 100
.
.
P(99 Black) = 0.01 100

----------------------------------------------------- +
P(with 1 or some black) =  0.572....

P (all white) = 1
P (all white) : P(some black) = 1 : 0.572

Conclusion : do not take the bet !!

18. ### Marathon (mini) puzzles (trapped in a dungeon)

I have a solution it can be really stright, not just by add S in front

19. ### Marathon (mini) puzzles (trapped in a dungeon)

I have a solution it can be really stright, not just by add S in front

20. ### 100 white marbles

fore case 2, I have run a computer simulation, which show that you should not bet.

The probability that all white is only .63

so the quite fair bet is 2:1  not  5:1

21. ### 100 white marbles

There are 2 cases

case 1. Someone want to fool you, he just put one black
case 2. Nobody try to fool, maybe there are no black,1 or more than one black.

in case 1 :
you should not take the bet.
there is 35% probability that in 100 tries you cannot find the black one.

in case 2 :
I still confuse how to solve this case.

22. ### IQ test question

Yes, I can agree with that logic. Thanks.

In creating a question in An IQ test, the creator must make sure that there is no double interpreatation to the question (the question can be answered differently)

1,2,....

a. 3
b. 4
c. 5

because there is a double interpretation there

but b.4 is also correct, because : 20 = 1,   21 = 2,   22 = 4

so to avoid this, one of the correct answer must be removed from the question.

-------

in the question above you may think the logic that I over is questionable.
But it also acceptable, so if the question maker do not allow my logic, so he must
prevent this kind of logic appear, so he must create another option that is also not a duplicate.

but since my logic, and pavan logic come to one option, so this is still acceptable.

So, if we have found a logic in an IQ test question, just use it.

23. ### 100 white marbles

No, You can be deceived, if there is just 1 black,2 blacks or even 10 blacks marble there, and you are unlucky to find the black marble.

24. ### Bloody Roulette game

I think:

Hidden Content

Right answer, but I'm sure some of us still wonder why.

Let's cek the combinations
note (x,y) means : bullet at  xth hole in gun1 and bullet at yth hole in gun2
since gun1 is shot 1st so if x<= y then means 1st player win.
so (1,1) or (2,2) means 1st player win.

for 2 holes and 1 hole guns
(1,1) 1st win
(2,1) 2nd win

for 3 holes and 2 holes guns
(1,1) 1st win (1,2) 1st win
(2,1) 2nd win (2,2) 1st win
(3,1) 2nd win (3,2) 2nd win

for 4 holes and 3 holes guns
(1,1) 1st win (1,2) 1st win (1,3) 1st win
(2,1) 2nd win (2,2) 1st win (2,3) 1st win
(3,1) 2nd win (3,2) 2nd win (3,3) 1st win
(4,1) 2nd win (4,2) 2nd win (4,3) 2nd win

for 5 holes and 4 holes guns
(1,1) 1st win (1,2) 1st win (1,3) 1st win (1,4) 1st win
(2,1) 2nd win (2,2) 1st win (2,3) 1st win (2,4) 1st win
(3,1) 2nd win (3,2) 2nd win (3,3) 1st win (3,4) 1st win
(4,1) 2nd win (4,2) 2nd win (4,3) 2nd win (4,4) 1st win
(5,1) 2nd win (5,2) 2nd win (5,3) 2nd win (5,4) 2nd win

and so on....

if we pay attention at the combinations above, they create pattern of 2 triangle

1st player win at upper triangle and 2nd player win in lower triangle
both triangle are same size, so both player have same chance to win.

25. ### IQ test question

1 2 3 4

5 6 7 8

if I label the options like number 1 to 8 above

I think the answer is number 4

all other shape are duplicates, only number 4 is not a duplicate

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