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Forums > General Discussion   Shooting the breeze...

rice on a chessboard quick quiz

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Created by Craig66 > 9 months ago, 5 Apr 2020
Craig66
NSW, 2466 posts
5 Apr 2020 9:19AM
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If someone gave you a chessboard and asked you to put one grain of rice on the first square, two grains of rice on the second square, four grains of rice on the third, eight grains on the fourth, and so on, how many grains of rice would end up on the 64th square?

Imax1
QLD, 4926 posts
5 Apr 2020 9:30AM
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Enough for a mushroom and truffle risotto ?

Slack
WA, 685 posts
5 Apr 2020 7:45AM
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9.223372e+18

Harrow
NSW, 4521 posts
5 Apr 2020 9:50AM
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267 trillion tonnes

Marvin
WA, 725 posts
5 Apr 2020 7:51AM
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Impossible

Vince68
WA, 675 posts
5 Apr 2020 7:55AM
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9,223,372,036,854,775,808

Mr Milk
NSW, 3116 posts
5 Apr 2020 10:14AM
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How big are the squares?

Gorgo
VIC, 5108 posts
5 Apr 2020 11:08AM
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Not many. Most of them would be on the floor because they fell off.

Craig66
NSW, 2466 posts
5 Apr 2020 11:12AM
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Vince68 said..
9,223,372,036,854,775,808



You must have read the same article.... or you just a Smarty Pants

You'd need 9,223,372,036,854,775,808 grains of rice for the 64th square.

That's nine quintillion, two hundred and twenty-three quadrillion, three hundred and seventy-two trillion, thirty-six billion, etc, grains.
And the amount of rice you'd need to cover the entire board - from squares 1 to 64 - would be 18.4 quintillion grains.

That's 923 times the entire estimated global production of rice this financial year.

seapig
TAS, 71 posts
5 Apr 2020 11:18AM
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Rice? You can still buy rice ??????

Buster fin
WA, 2596 posts
5 Apr 2020 10:04AM
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Lice? Haven't seen that since the kids were at school.

Harrow
NSW, 4521 posts
5 Apr 2020 12:46PM
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Buster fin said..
Lice? Haven't seen that since the kids were at school.

Craw, not Craw! Just pulled out the old Get Smart DVD series for the kids to watch.

Pacey
WA, 525 posts
5 Apr 2020 12:21PM
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To put this in perspective with COVID-19, if you have 1 infected person in the community and the doubling time for infections is 3 days, after 30 days you will have about 1,000 infected people, after 60 days you will have 1,000,000 infected people.

Obviously in the real world the number of uninfected people will be dropping at the same time and eventually the infection rate will plateau, but by that time your hospital system is already overwhelmed. That's why social distancing is so important in order to slow the rate of increase.

Craig66
NSW, 2466 posts
5 Apr 2020 2:49PM
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Pacey said..
To put this in perspective, old mate at the corona factory gave one to another mate to share and so on, , after 30 days you will have about 1,000 drunk people, after 60 days you will have a huge party


fixed it

Harrow
NSW, 4521 posts
5 Apr 2020 5:32PM
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So, we managed to have slowed the spread to a very modest number....only problem now is that in 3, 6, or 9 months we will be in exactly the same position as we are now. Relax the restrictions and it takes up where it left off.

That means 3 courses of action:

1. Relieve restrictions and have a full-blown outbreak
2. Leave restrictions on until vaccine is ready...another year?
3. Eradicate through total isolation measures and mass testing. Possible when the 15-minute test is widely available.

If you choose option 1, you might as well do it right away.
If you choose option 2, really, we want to wait out another year of this? Which takes you back to option 1 or option 3.
When will option 3 be possible....testing tech seems to be advancing quickly.

NotWal
QLD, 7433 posts
5 Apr 2020 6:20PM
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2^64 -1 = all the rice on the board - big board.

NotWal
QLD, 7433 posts
5 Apr 2020 6:29PM
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Harrow said..
So, we managed to have slowed the spread to a very modest number....only problem now is that in 3, 6, or 9 months we will be in exactly the same position as we are now. Relax the restrictions and it takes up where it left off.

That means 3 courses of action:

1. Relieve restrictions and have a full-blown outbreak
2. Leave restrictions on until vaccine is ready...another year?
3. Eradicate through total isolation measures and mass testing. Possible when the 15-minute test is widely available.

If you choose option 1, you might as well do it right away.
If you choose option 2, really, we want to wait out another year of this? Which takes you back to option 1 or option 3.
When will option 3 be possible....testing tech seems to be advancing quickly.


4. Maintain restrictions until herd immunity is achieved. That is most of the population gets exposed and everyone who needs it gets the medical attention they need.

FormulaNova
WA, 15090 posts
5 Apr 2020 4:37PM
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NotWal said..

Harrow said..
So, we managed to have slowed the spread to a very modest number....only problem now is that in 3, 6, or 9 months we will be in exactly the same position as we are now. Relax the restrictions and it takes up where it left off.

That means 3 courses of action:

1. Relieve restrictions and have a full-blown outbreak
2. Leave restrictions on until vaccine is ready...another year?
3. Eradicate through total isolation measures and mass testing. Possible when the 15-minute test is widely available.

If you choose option 1, you might as well do it right away.
If you choose option 2, really, we want to wait out another year of this? Which takes you back to option 1 or option 3.
When will option 3 be possible....testing tech seems to be advancing quickly.



4. Maintain restrictions until herd immunity is achieved. That is most of the population gets exposed and everyone who needs it gets the medical attention they need.


I think that option is the safest health wise, but would take a very long amount of time.

You might be better off dosing up otherwise healthy people, letting them get over it, and then releasing them into the community? It would be faster, but at more risk and cost.

Harrow
NSW, 4521 posts
5 Apr 2020 7:10PM
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NotWal said..
4. Maintain restrictions until herd immunity is achieved. That is most of the population gets exposed and everyone who needs it gets the medical attention they need.

Nope, we don't need a number 4, that's covered by either 1 or 2, achieving herd immunity in a fast or slow fashion, and option 2 is so slow that the vaccine will be ready first.

NotWal
QLD, 7433 posts
5 Apr 2020 8:05PM
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^ No it's not. The difference is maintaining an ability of the medical crew to remain effective, although that may be concomitant with 2.

Harrow
NSW, 4521 posts
5 Apr 2020 8:16PM
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NotWal said..
^ No it's not. The difference is maintaining an ability of the medical crew to remain effective, although that may be concomitant with 2.

Do the calculations and you'll see that it if you slow things down enough to maintain effective medical treatment, it will take a couple of years to reach herd immunity, so the vaccine will most likely come along first, thus number 2.

AusMoz
QLD, 1510 posts
5 Apr 2020 8:30PM
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After reading all this, i don't like chess or rice any more

Craig66
NSW, 2466 posts
5 Apr 2020 9:01PM
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AusMoz said..
After reading all this, i don't like chess or rice any more


Check Mate

I was thinking a bit of humor would be fun.
But my bad to think we could avid thread hijack

FormulaNova
WA, 15090 posts
5 Apr 2020 8:14PM
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Craig66 said..

AusMoz said..
After reading all this, i don't like chess or rice any more



Check Mate

I was thinking a bit of humor would be fun.
But my bad to think we could avid thread hijack



I think I have read that some question used very recently to explain the growth of Covid19 infections, so you can't really be surprised that that's where its ended up can you?



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Forums > General Discussion   Shooting the breeze...


"rice on a chessboard quick quiz" started by Craig66