riddle 5...solved by finn...riddle 6...solved by C_stripes...

[captnsim]

What row of numbers comes next in this series?


1
11
21
1211
111221
312211
13112221

[Finn]

1
11
21
1211
111221
312211
13112221

Next: 1113213211
(one one, one three...)
No google. 
My grandparents have a ton of books and the riddle ones were my favorite.

[captnsim]

You manufacture entrainment CDs for companies that sell self-improvement products. You are at the post office, with ten boxes of them ready to close up and ship out, but you have a problem. Nine of the boxes contain CDs that are designed to put the listener into an "a" or relaxing state, and one is full of Cds that are designed to put the user into a deeper "d" state, for deep sleep. They look identical, and you forgot to label them.

There is one difference, however. You remember that the "a" Cds weigh 13 grams, and because different CD "blanks were used, the "d" Cds weigh 15 grams. Unfortunately, you can't feel the difference in weight by lifting them.

The post office does have a scale. It costs one dollar each time you weigh something, though, and you want to keep your costs down. How do you use the scale as few times as possible to determine which are the "d" CDs?

[lisiecki1]

take one cd out of each box and weigh all 10 at once and note how much the weight changes as you remove them one by one.....cost $1

[Troy]

First, take a CD from each box and look at the CDs to see if the manufacturer put a part number on them. The oddball is the 'd'.
Total: $0

Otherwise...
Put a CD from each of the ten boxes into three stacks of three plus a single CD. Weigh each stack ($3). If they are the same then the single CD is the "d".
Total: $3

If the three stacks are different weights, split the heaviest stack and weigh each of the single CDs stopping once you find the 15g CD ($1-3).
Total: $4-6

Alternatively...
Put a CD from each of the ten boxes into two stacks of five CDs. Weigh each stack ($2). Set aside the lighter stack and split the heaviest stack into two stacks of two CDs and a single CD. Weigh the two bigger stacks ($2). If they are the same then the single CD is the "d".
Total: $4

If the two stacks are different weights, split the heaviest stack and weigh each of the single CDs stopping once you find the 15g CD ($1-2).
Total: $5-6

Troy

[captnsim]

Those are all good guesses... I'll give a hint...Their is a way to do this for a dollar, and tell which box it is...without a doubt...Also the scale is a instant read...one readout = one dollar...

[Finn]

Hmm. Is the scale a must use item?
Slip a post worker a dollar and have him put the cds into a computer. (better yet go to car and do it)
or
Attach a note saying "one of these boxes contains D-CDs".

I'm guessing neither or those are it. 

[captnsim]

Nope not it...But creative none the less...    

[captnsim]

Clue.....Step one....Number the boxes 1 thru 10....

#55

Hope this helps

[Troy]

Ha! I can do it for free...

the Post Office must weigh the boxes to determine postage owed.

Troy

[captnsim]

Ha Ha, This post office charges for that service...once you figure out how the clue above applies the rest will be easy...

[500hp_440]

Any body can tell difference in weight by picking them up, pick up all 10 1 or 2 at a time and take the heaviest or lightest (which ever D is) and weigh it, if your right you spend $1 if your not take all 10

[captnsim]

Did you read paragraph two???

[resq302]

Put all of the boxes on the scale.  Pull one off at a time and keep track of what ounce of weight gets removed from the scale.  Therefore, you are just subtracting the total amount of weight and it is never removing boxes or setting the scale back to zero.  Which ever box ends up weighing 15 grams is the box with the "d" cd's.

[captnsim]

If only it was that easy...1 dollar = 1 readout. Take anything off and you need to put in another dollar...You have part of it figured out...This can be done...with one dollar and no funny stuff.

[Troy]

Did you read paragraph two???

Are you kidding? Read? What nonsense is this?

Troy

[captnsim]

You manufacture entrainment CDs for companies that sell self-improvement products. You are at the post office, with ten boxes of them ready to close up and ship out, but you have a problem. Nine of the boxes contain CDs that are designed to put the listener into an "a" or relaxing state, and one is full of Cds that are designed to put the user into a deeper "d" state, for deep sleep. They look identical, and you forgot to label them.

There is one difference, however. You remember that the "a" Cds weigh 13 grams, and because different CD "blanks were used, the "d" Cds weigh 15 grams. Unfortunately, you can't feel the difference in weight by lifting them.

The post office does have a scale. It costs one dollar each time you weigh something, though, and you want to keep your costs down. How do you use the scale as few times as possible to determine which are the "d" CDs?

500hp stated you could feel the differance by picking them up...

[C_stripes]

Did you read paragraph two???

Are you kidding? Read? What nonsense is this?

Troy

lmao.  Some people are to cool to read. ...or spell.  

I know, sometimes I don't spell perfectly. Who does 100%?

Who can feel the difference in a few grams?  No one I have ever met. That's very little weight.

I have been trying to figure this out and I can't see how it could be done unless you broke down the boxes into two sets of five, then you break the heaviest down to two of two and hope that one of the stacks of two. If they both are the same, the one that was left off is the case in question. If one weighs more. Then separate those two and weigh individually. Your cost would be between four and five dollars that way.

Where are you getting all of these captnsim?

[Troy]

You manufacture entrainment CDs for companies that sell self-improvement products. You are at the post office, with ten boxes of them ready to close up and ship out, but you have a problem. Nine of the boxes contain CDs that are designed to put the listener into an "a" or relaxing state, and one is full of Cds that are designed to put the user into a deeper "d" state, for deep sleep. They look identical, and you forgot to label them.

There is one difference, however. You remember that the "a" Cds weigh 13 grams, and because different CD "blanks were used, the "d" Cds weigh 15 grams. Unfortunately, you can't feel the difference in weight by lifting them.

The post office does have a scale. It costs one dollar each time you weigh something, though, and you want to keep your costs down. How do you use the scale as few times as possible to determine which are the "d" CDs?

500hp stated you could feel the differance by picking them up...

I was poking fun at the youngster.

Troy

[69CoronetRT]

 

[captnsim]

I will never tell...This one is a bit devilish...  55 is a amount...

[Finn]

Hang on, do the CDs weigh w/e the amount was or is that the box they are in?

[Troy]

That's 2 grams per cd. The boxes are "full of CDs" so 100 CDs would be about 1/2 pound difference per box.

You sure I didn't answer this already but by weighing individual CDs instead of whole boxes? (Split into 5, then 2, then 1?) Boxes could have packing material and other weight differences but the CDs are a known weight.

55 is the total of all the numbers written on the boxes.

Troy

[captnsim]

My bodyman can tell difference in weight by picking them up, pick up all 10 1 or 2 at a time and take the heaviest or lightest (which ever D is) and weigh it, if he is right ( he always is) you spend $1 if he is not take all 10

I fix for him...But he still wrong
Box is not a factor...

[Troy]

Aw, dang!

Ok, I got it but I cheated so I won't answer.

Troy

[C_stripes]

You have to take the cds out of the box. 1 out of one box, 2 out of the next and so on, then you calculate the weight and you can figure how what box has the heavy ones by doing the math. I still don't understand the 55 though.

[captnsim]

SO close...can you put it together??

[C_stripes]

Got the 55, 1 out of box 1. 2 out of box 2. etc... but I don't know where to go from there because the math I am doing doesn't add up.

55 is the amount of CD's that will be on the scale. So now its all times and divide, I just don't know where to go.

[captnsim]

Even closer...You basically have it...All your trying for is the formula to find the box...The box can be any one of the ten...

[Finn]

Alright I might be off *darn thing occupied most of my time during the orientation to one of my classes. I was asking my friends if they have ever heard it before...also stumped my engineering teacher with it  * but I think Troy is on the right track but with the wrong numbers. You put the CDs on the scale but with a set number number from each box, hence the 1 through 10 for clarification right?
We can calculate the weight of all the A CDs which comes out too...

*I just went back to copy it and work out the math but c_stripes pretty much posted my idea up*

[C_stripes]

I have 715 total grams if they were all 13 grams. so now I just need to figure out how to calculate it so that I can find out where the 15 gram ones are.

Help?

[captnsim]

you all are sooo close....

[Finn]

Ah since its still open you put the cds on the scale like C_stripes said, 55 cds in total.
W/e the total weight is on that (the 1 dollar part) you can subtract the weight of the total of the A CDs and then divide that by the difference in the weight between A and B CDs which I think gives you a number that corresponds to to however many you took out of box so and so, which would be the box of the heavy CDs.


PHEW.

??

[C_stripes]

Duh!! There really is no way FOR US to know the box. But the way to find out is to take the total amount and subtract the 715 from it.

So if the scale said 719, you subtract 715 and come out with four. Which means that box two has the cd's.  

Am I right??

[Finn]

I believe so but my brain hurts a bit lol.

[captnsim]

Congrats, C_stripes...nice thinking...

[C_stripes]

Crazy,  Now I need to do my homework. your riddles keep distracting me.  lol

[resq302]

    aarrrrgggghhh.  all this thinking is making my brain hurt.   (and I still don't get it)

[captnsim]

I figured I'd post the whole answer for this one in one post.

You can determine which box has the "d" CDs in it by using the scale just one time. Here's how:

Label the boxes 1 through 10. Put one CD from box number one on the scale. Then, on top of that, put two CDs from box number two. Then put three from box number three on those, four from box four, and so on.

There are now 55 CDs on the scale. Pay the dollar and see what the total weight is. If they were all 13 grams, the total weight would be 715 grams (55 x 13). However, you know that one or more of the CDs weighs 15 grams.

Subtract 715 grams from the total weight, and this gives you the "extra weight" for the heavier CDs. Since you know that they are each two grams heavier than the others, you can divide this excess weight by two, and the result tells you how many of the heavier Cd's are on the scale, and this number tells you which box contains the "d" CDs.

For example, if the weight is 727 grams, you would subtract 715 from this, leaving you with 12 grams of "excess weight." Divide this by 2, and you know that there are 6 of the heavier CDs on the scale. Since the number of CDs from each box coincides with the number assigned to that box, you now know that box number six has the "d" CDs.