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Old Feb 9, 2008, 06:53 PM   #76
CalBoy
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There are two known ways to make $1.00 out of 50 coins, what are they? Assuming that we are using American currency: $.01 $.05 $.10 $.25 $.50
Do we have to use precisely 50 coins?
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Old Feb 9, 2008, 07:00 PM   #77
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Can someone spot what this pattern is, and in doing so find what starting (numbers) have a finite sequence:

1: 1, 11, 21, 1112, 3112, 211213, 312213, 212223...
2: 2, 12, 1112, 3112...
3: 3, 13, 1113, 3113, 2113, 211213...
4: 4, 14, 1114, 3114, 211314, 31121314, 41122314, 31221324...
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Old Feb 9, 2008, 07:02 PM   #78
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Originally Posted by JML42691 View Post
There are two known ways to make $1.00 out of 50 coins, what are they? Assuming that we are using American currency: $.01 $.05 $.10 $.25 $.50
2*$0.10, 8*$0.05, 40*$0.01
1*$0.25, 2*$0.10, 2*$0.05, 45*$0.01
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Old Feb 9, 2008, 07:07 PM   #79
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Originally Posted by psychofreak View Post
Can someone spot what this pattern is, and in doing so find what starting (numbers) have a finite sequence:

1: 1, 11, 21, 1112, 3112, 211213, 312213, 212223...
2: 2, 12, 1112, 3112...
3: 3, 13, 1113, 3113, 2113, 211213...
4: 4, 14, 1114, 3114, 211314, 31121314, 41122314, 31221324...
It's verbal. Each term is gotten by 'reading' the previous term.

For example, the top sequence starts with a 1 (or one 1), so the next term is 11, that is read as two 1's so the next term is 21, that is read as one 1, one 2, or 1112, and so on.

Edit: There seems to be a typo in sequence 3
3: 3, 13, 1113, 3113, 2123, 112213...

Edit2: None of the sequences are finite, but the sequence starting at 22 will just be 22,22,22,22,22,...

Last edited by swiftaw; Feb 9, 2008 at 07:17 PM.
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Old Feb 9, 2008, 07:19 PM   #80
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Do we have to use precisely 50 coins?
Yes, but now it has been solved, I figured that it would take people a little longer than that.
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Old Feb 9, 2008, 07:20 PM   #81
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How do you make 1000 by adding eight 8s?
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Old Feb 9, 2008, 07:22 PM   #82
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How do you make 1000 by adding eight 8s?
Adding?

Can we perform any operations other than adding?
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Old Feb 9, 2008, 07:22 PM   #83
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How do you make 1000 by adding eight 8s?
888+88+8+8+8
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Old Feb 9, 2008, 07:23 PM   #84
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888+88+8+8+8
Something leads me to believe you've heard of a few of these before.
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Old Feb 9, 2008, 07:24 PM   #85
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Something leads me to believe you've heard of a few of these before.
Actually, no, I'm just pretty good with numbers
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Old Feb 9, 2008, 07:26 PM   #86
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Actually, no, I'm just pretty good with numbers
Well that explains that!

See I suck horribly at them.
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Old Feb 9, 2008, 07:33 PM   #87
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so do you want the spreadsheet back, with my name??
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Old Feb 9, 2008, 07:42 PM   #88
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Just going back to the original cat problem in post #1. The question says the girls are on the bus and the backpacks are on the bus and the big cats are in the backpacks so they are also on the bus...

BUT...

It doesn't say where the little cats are... so... it is just as valid to assume that the little cats are not on the bus so you do not count their legs...
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Old Feb 9, 2008, 08:02 PM   #89
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Just going back to the original cat problem in post #1. The question says the girls are on the bus and the backpacks are on the bus and the big cats are in the backpacks so they are also on the bus...

BUT...

It doesn't say where the little cats are... so... it is just as valid to assume that the little cats are not on the bus so you do not count their legs...
Finally someone who was confused like myself. Makes me feel like less of an idiot now.

At least I got this great thread started with some very interesting math problems.
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Old Feb 9, 2008, 08:04 PM   #90
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It doesn't say where the little cats are... so... it is just as valid to assume that the little cats are not on the bus so you do not count their legs...
It also doesn't mention how many boys, adults, centipedes, or pianos are in the bus, so, yes, it's poorly specified.
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Old Feb 9, 2008, 09:33 PM   #91
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It also doesn't mention how many boys, adults, centipedes, or pianos are in the bus, so, yes, it's poorly specified.
I'm still trying to figure out who's driving the bus, and how many legs they may (or may not) have.
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Old Feb 9, 2008, 10:57 PM   #92
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Quote:
Originally Posted by xlii View Post
Just going back to the original cat problem in post #1. The question says the girls are on the bus and the backpacks are on the bus and the big cats are in the backpacks so they are also on the bus...

BUT...

It doesn't say where the little cats are... so... it is just as valid to assume that the little cats are not on the bus so you do not count their legs...
lol just work out the problem however you can, and try inputting it into the spreadsheet's password. you'll get it eventually, i'm sure. it wasnt that hard lol

Now i just want to know if the spreadsheet should be uploaded after imputting my name, or something...
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Old Feb 9, 2008, 11:20 PM   #93
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Ok, since you asked.

There are 3 doors. Behind 1 door lies immense wealth and riches. Behind the other two lie certain death.

A guard asks you to choose a door and you pick #2. The guard then reveals to you what's behind Door #1 and you see that behind it was one of two chances of certain death.

The guard now asks you if you would like to change your selection from Door #2 to Door #3.

Mathematically is there a probability increase that benefits you if you change doors?

BTW, I don't know the answer to this, but I've seen it thrown around a few times
Yes. You're always better off switching.
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Old Feb 9, 2008, 11:22 PM   #94
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This one stumped me for a long time. I felt so stupid when i realized how easy it was.

"You are a bus driver. At your 1st stop you pick up 20 people. At your 2nd you drop off 10 and pick up 13. At your 3rd stop you drop off 11 and pick up 24. And at your 4th stop you pick drop off 7 people and pick up 9. What colour are the bus driver's eyes?"
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Old Feb 9, 2008, 11:24 PM   #95
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This one stumped me for a long time. I felt so stupid when i realized how easy it was.

"You are a bus driver. At your 1st stop you pick up 20 people. At your 2nd you drop off 10 and pick up 13. At your 3rd stop you drop off 11 and pick up 24. And at your 4th stop you pick drop off 7 people and pick up 9. What colour are the bus driver's eyes?"
Blue.

...That's a classic, although every time I've heard it, it ended with "How old is the bus driver?".
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Old Feb 9, 2008, 11:25 PM   #96
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It also doesn't mention how many boys, adults, centipedes, or pianos are in the bus, so, yes, it's poorly specified.
A bus has stopped and the driver and all passengers, pets, and other living creatures have gotten off, except that one centipede remains on the floor under a seat. On top of the same seat is a take-out food carton, in which a passenger accidentally left a turkey leg and a lucky rabbit's foot.

How many legs are on the bus?
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Old Feb 10, 2008, 12:02 AM   #97
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Ok, since you asked.

There are 3 doors. Behind 1 door lies immense wealth and riches. Behind the other two lie certain death.

A guard asks you to choose a door and you pick #2. The guard then reveals to you what's behind Door #1 and you see that behind it was one of two chances of certain death.

The guard now asks you if you would like to change your selection from Door #2 to Door #3.

Mathematically is there a probability increase that benefits you if you change doors?

BTW, I don't know the answer to this, but I've seen it thrown around a few times
This is a classic problem known as the Monty Hall problem. It is a classic example in conditional probability. If you don't switch the probability of winning is 1/3, if you do switch it is 2/3, so you should always switch.
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Old Feb 10, 2008, 12:09 AM   #98
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A bus has stopped and the driver and all passengers, pets, and other living creatures have gotten off, except that one centipede remains on the floor under a seat. On top of the same seat is a take-out food carton, in which a passenger accidentally left a turkey leg and a lucky rabbit's foot.

How many legs are on the bus?
The problem remains insufficiently specified, as centipedes - assuming non-mutant ones with all of their legs - have between 30 (the typical number) and 354 legs. We at least need to know the species.

And there was no mention of the occurrence or lack thereof of non-biological legs.
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Old Feb 10, 2008, 12:19 AM   #99
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The problem remains insufficiently specified.
That is the correct answer. But you should have waited for somebody else to say 101, so we could tease them for not knowing their entomology.

There could also be legs on the bus seats, but we'll ignore that.
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Old Feb 10, 2008, 12:26 AM   #100
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is the answer to the OPs problem 10990?
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