Author: karyasarma

Tukang Kayu

Seorang tukang kayu membutuhkan waktu 4 menit untuk membelah kayu menjadi 4 bagian. Berapa waktu yang dibutuhkannya untuk membelah kayu tersebut menjadi 3 bagian?

Jawaban

8/3 menit.

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Penjelasan

Untuk membelah kayu menjadi 4 bagian, tukang kayu hanya membutuhkan 3 kali pembelahan. Setiap pembelahan memakan waktu 4/3 menit.

Untuk membelah kayu menjadi 3 bagian, tukang kayu hanya membutuhkan 2 kali pembelahan dengan waktu 2 x (4/3 menit) = 8/3 menit.

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Playing Games With Eternity: The Devil’s Offer

by Edward J. Gracely

Suppose Ms C dies and goes to hell, or to a place that seems like hell. The devil approaches and offers to play a game of chance. If she wins, she can go to heaven. If she loses, she will stay in hell forever; there is no second chance to play the game. If Ms C plays today, she has a 1/2 chance of winning. Tomorrow the probability will be 2/3. Then 3/4, 4/5, 5/6, etc., with no end to the series. Thus every passing day increases her chances of winning. At what point should she play the game?

The answer is not obvious; after any given number of days spent waiting, it will still be possible to improve her chances by waiting yet another day. And any increase in the probability of winning a game with infinite stakes has an infinite utility. For example, if she wait a year, her probability of winning the game would be approximately .997268; if she waits one more day, the probability would increase to .997275, a difference of only .000007. Yet, even .000007 multiplied by infinity is infinite.

On the other hand, it seems reasonable to suppose the cost of delaying for a day to be finite — a day’s more suffering in hell. So the infinite expected benefit from a delay will always exceed the cost.

This logic might suggest that Ms C should wait forever, but clearly such a strategy would be self defeating: why should she stay forever in a place in order to increase her chances of leaving it? So the question remains: what should Ms C do?

© Edward J. Gracely June 1988

Matchstick Puzzle #1

Matchstick 1 Floor House to 2 Floor House

Buatlah rumah 1 tingkat di atas menjadi 2 tingkat dengan memindahkan korek api sesedikit mungkin.

Jawaban

Tidak perlu memindahkan korek api, cukup dengan memutar gambar di atas -90°. Hasilnya bisa dilihat pada gambar di bawah ini.

Matchstick 1 Floor House to 2 Floor House Answer

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Quiz Parampaa

Use ruffle.rs to play the Flash on your browser.

Password

Level 11: eleven
Level 21: twenty1
Level 29: bartman
Level 31: thirty1
Level 41: fourty1
Level 52: fifty2
Level 67: sunset
Level 71: dorayaki
Level 80: linger
Level 90: gomugomu

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Bloxorz

Use ruffle.rs to play the Flash on your browser.

Password

Level 01: 780464
Level 02: 290299
Level 03: 918660
Level 04: 520967
Level 05: 028431
Level 06: 524383
Level 07: 189493
Level 08: 499707
Level 09: 074355
Level 10: 300590
Level 11: 291709
Level 12: 958640
Level 13: 448106
Level 14: 210362
Level 15: 098598
Level 16: 000241
Level 17: 683596
Level 18: 284933
Level 19: 119785
Level 20: 543019
Level 21: 728724
Level 22: 987319
Level 23: 293486
Level 24: 088198
Level 25: 250453
Level 26: 426329
Level 27: 660141
Level 28: 769721
Level 29: 691859
Level 30: 280351
Level 31: 138620
Level 32: 879021
Level 33: 614955

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I Am Your Age Plus Half Of My Age

My son asked me, “How old are you?”

And in reply, I said, “I am your age plus half of my age.”

My son is 22, how old am I?

Answer

44 years old.

Explanation:

x = father’s age

ABCDEx = 22 + ½x
x – ½x = 22
ABCD½x = 22
ABCDEx = 44

Q.E.D.

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