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Math12-04-2021 06:20
James___
★★★★★
(5118)
3 guys pay $10 each for a shared room. That is $30. The desk clerk decides to give them a discount of $5. Since that is not split 3 ways, they are each given a $1 discount. That means that they each paid $9 and the desk clerk kept $2.

And we know that $9 x 3 (what was paid for the room) + $2 (what the desk clerk kept) = $29. Where did the missing dollar go?
12-04-2021 15:52
IBdaMannProfile picture★★★★★
(10017)
James___ wrote:
3 guys pay $10 each for a shared room. That is $30. The desk clerk decides to give them a discount of $5. Since that is not split 3 ways, they are each given a $1 discount. That means that they each paid $9 and the desk clerk kept $2.

And we know that $9 x 3 (what was paid for the room) + $2 (what the desk clerk kept) = $29. Where did the missing dollar go?


This is my usual go-to problem for kids. I call it the "Stolen Dollar at the $30 Hotel" problem. At the $30 Hotel all rooms cost $30. When the three travelers arrive they each pay the $10 they each have individually. The room has a damaged air conditioner so the clerk sends a refund of $5 to the room via the bell hop. Each traveler receives $1 and the bell hop gets two dollars as a tip.

Each traveler ended up paying $9 (x3=$27) and the bell hop got $2 which adds up to $29. How did the clerk manage to steal the remaining dollar? This problem is an excellent example of the actual mechanics of how Global Warming gibber-babble works, i.e. lot's of intentionally confusing superfluous "set up" in order to slip bad math by you without you noticing.

SPOILER - In this case the person posing the stolen dollar problem calculates the $27 paid by the travelers and then deceptively ADDS the $2 received by the bell hop, bringing the number in question to $29 instead of properly SUBTRACTING the $2 and bringing the number in question to $25, i.e. the amount paid for the room.

This is similar to Pete Roger's addition of nonexistent negative work. He gibbers and babbles about gravity and compressed atmosphere for a few paragraphs as a setup and then he sneaks in the "negative work" and tells us that it adds up to a temperature increase without additional energy ... because air pressure is weight ... or whatever the variation of the day happens to be.

12-04-2021 16:51
HarveyH55Profile picture★★★★★
(3658)
Yeah, my algebra teacher in high school had dozens of those gotcha math problems, almost every week, for extra credit. I didn't need the extra credit, and didn't often bother. I generally did my homework, while teachers talked, so I didn't have to carry books around, any more than I had to. I found that most teachers, just repeat, what is already in the books, answer questions, for those struggling, very repetitious, if you got it the first time around. I'd pay closer attention, when we had a test coming up, since that's where most of the test answers were found...
12-04-2021 17:32
gfm7175Profile picture★★★★★
(2466)
Yeah, I've seen that misleading question pop up on some forum before and I had to explain the bad math behind it.
12-04-2021 18:29
Into the NightProfile picture★★★★★
(16138)
James___ wrote:
3 guys pay $10 each for a shared room. That is $30. The desk clerk decides to give them a discount of $5. Since that is not split 3 ways, they are each given a $1 discount. That means that they each paid $9 and the desk clerk kept $2.

And we know that $9 x 3 (what was paid for the room) + $2 (what the desk clerk kept) = $29. Where did the missing dollar go?


It didn't go anywhere. Bad math.

The clerk didn't give them a discount of $5. He game them a discount of $3, so each guest paid $9, not $10 for the room, totaling $27, not $30. Each guest kept the remaining dollar, adding up to the $3 to make the $30.

Done.


The Parrot Killer

Debunked in my sig. - tmiddles

Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit

nuclear powered ships do not require nuclear fuel. - Swan
12-04-2021 20:07
SwanProfile picture★★★☆☆
(571)
James___ wrote:
3 guys pay $10 each for a shared room. That is $30. The desk clerk decides to give them a discount of $5. Since that is not split 3 ways, they are each given a $1 discount. That means that they each paid $9 and the desk clerk kept $2.

And we know that $9 x 3 (what was paid for the room) + $2 (what the desk clerk kept) = $29. Where did the missing dollar go?


Is this a brain teaser for numbnuts? There is no missing dollar if the writer can do math themselves?

Now if the real price of the room was 20 dollars and to cover the deceit of charging the men 30 dollars the clerk gave a 5 dollar rebate that she increased to 6 and kept a missing dollar all to cover give the gay men the idea that they were getting a discount when they were actually getting robbed.

Done.

Since no hotel room has 3 beds the men were gay
14-04-2021 17:00
James___
★★★★★
(5118)
Into the Night wrote:
James___ wrote:
3 guys pay $10 each for a shared room. That is $30. The desk clerk decides to give them a discount of $5. Since that is not split 3 ways, they are each given a $1 discount. That means that they each paid $9 and the desk clerk kept $2.

And we know that $9 x 3 (what was paid for the room) + $2 (what the desk clerk kept) = $29. Where did the missing dollar go?


It didn't go anywhere. Bad math.

The clerk didn't give them a discount of $5. He game them a discount of $3, so each guest paid $9, not $10 for the room, totaling $27, not $30. Each guest kept the remaining dollar, adding up to the $3 to make the $30.

Done.



Well done ITN.
14-04-2021 17:27
gfm7175Profile picture★★★★★
(2466)
James___ wrote:
Into the Night wrote:
James___ wrote:
3 guys pay $10 each for a shared room. That is $30. The desk clerk decides to give them a discount of $5. Since that is not split 3 ways, they are each given a $1 discount. That means that they each paid $9 and the desk clerk kept $2.

And we know that $9 x 3 (what was paid for the room) + $2 (what the desk clerk kept) = $29. Where did the missing dollar go?


It didn't go anywhere. Bad math.

The clerk didn't give them a discount of $5. He game them a discount of $3, so each guest paid $9, not $10 for the room, totaling $27, not $30. Each guest kept the remaining dollar, adding up to the $3 to make the $30.

Done.



Well done ITN.

Good comment, James!
15-04-2021 00:34
James___
★★★★★
(5118)
gfm7175 wrote:
James___ wrote:
Into the Night wrote:
James___ wrote:
3 guys pay $10 each for a shared room. That is $30. The desk clerk decides to give them a discount of $5. Since that is not split 3 ways, they are each given a $1 discount. That means that they each paid $9 and the desk clerk kept $2.

And we know that $9 x 3 (what was paid for the room) + $2 (what the desk clerk kept) = $29. Where did the missing dollar go?


It didn't go anywhere. Bad math.

The clerk didn't give them a discount of $5. He game them a discount of $3, so each guest paid $9, not $10 for the room, totaling $27, not $30. Each guest kept the remaining dollar, adding up to the $3 to make the $30.

Done.



Well done ITN.

Good comment, James!



The actual solution is $27 paid by the 3 guys - $2 the bellhop kept equals $25 which is what the desk clerk kept.
15-04-2021 17:46
James___
★★★★★
(5118)
Here's another trick math problem.


I have 2 equations.

P= RT/(V-b) -a/(V^2) and

Ti= 2a/bR (1 - (b/V))^2

where V is the molar volume and Ti is the inversion temperature. How would I make an inversion curve out of this?

FYI I know the a and b values but I don't know V.

I need to plot at least 10 points for P between 0 and the max pressure.

I do know that the curve needs to be either an upside down or sideways parabola. I just need to know how to manipulate these equations to give that shape.


Someone posted this online.
Edited on 15-04-2021 17:49
16-04-2021 03:44
James___
★★★★★
(5118)
With the previous "trick" math problem, since V(olume) can't be negative, a parabola isn't possible.

This is a "trick" math problem that verifies a trig identity. It actually works.

1/
cos(x)sin(x) = csc(x)/cos(x)

This is because
1/
sin(x) = csc(x). And when divided by cos(x) is the same as dividing
1 by sin(x) times cos(x). Pretty Trick, right?
16-04-2021 06:01
IBdaMannProfile picture★★★★★
(10017)
James___ wrote: since V(olume) can't be negative,

Have you checked with Pete Rogers about that? Maybe force is applied over a negative volume to achieve negative work. Have you ever considered that? Maybe negative volumes are utilizing gravity this very moment to make the earth hotter than it otherwise should be.

You shouldn't be so carelessly dismissive. You'll never become an ancient Greek philosopher behaving in this manner.

16-04-2021 17:14
James___
★★★★★
(5118)
IBdaMann wrote:
James___ wrote: since V(olume) can't be negative,

Have you checked with Pete Rogers about that? Maybe force is applied over a negative volume to achieve negative work. Have you ever considered that? Maybe negative volumes are utilizing gravity this very moment to make the earth hotter than it otherwise should be.

You shouldn't be so carelessly dismissive. You'll never become an ancient Greek philosopher behaving in this manner.




I did mention that an example of negative work are the cables of a suspension bridge. When a bridge's road surface cannot fail which would be considered as
work = mass x distance, when this does not happen, it is because negative work is being performed.
A basic example is F = 1/2mv^2 divided by r. This is inertial force. A pendulum swings from the fulcrum because of the negative work of the line or rod that tethers it to the fulcrum.


p.s., not to be technical but when work = m * d. The distance that a tether/rod prevents a bob (what a weight on a pendulum is called) from moving is
-work = m * -d where -d is the distance not traveled and -work is the work not performed.
Edited on 16-04-2021 17:42
16-04-2021 19:17
IBdaMannProfile picture★★★★★
(10017)
James___ wrote:work = mass x distance,


James__,

Work = Force * Distance ... and Force = Mass * Acceleration

Ergo

Energy = Work = Mass * Acceleration * Distance

Power = Energy / Time = Work / Time

I hope this helps.



p.s., not to be technical but Work does not equal Mass * Distance. Enjoy!
16-04-2021 23:35
S@ve0ur3arth
☆☆☆☆☆
(24)
gfm7175 wrote:
Yeah, I've seen that misleading question pop up on some forum before and I had to explain the bad math behind it.

OMG I thought I was the only one who noticed that this question appears in almost every single forum you can imagine!
16-04-2021 23:41
James___
★★★★★
(5118)
IBdaMann wrote:
James___ wrote:work = mass x distance,


James__,

Work = Force * Distance ... and Force = Mass * Acceleration

Ergo

Energy = Work = Mass * Acceleration * Distance

Power = Energy / Time = Work / Time

I hope this helps.



p.s., not to be technical but Work does not equal Mass * Distance. Enjoy!



They need both a face palm and a sadly shaking head for emojis.

work is mass * distance. If a 1kg weight is moved 1 meter in 1 second of time, then it's velocity would have been 1 m/s (1m/1sec) which would allow for a force of 1kg * 1 m/s = 1n-m of force.
Force is measured in newtons or newton-meters. A 1kg weight has no force just as a 1 kg weight moving 1 meter at 9.81 m/s to get there would have 9.81n-m of force.
With energy, it is usually measured in eV or electron volts. And yes, power is usually associated with watts. Of course there is also horse power which is 745 watts or 745 j/s. My microwave oven has 1.476510067 horse power for cooking with if I need that much horse power.

Edited on 16-04-2021 23:43
17-04-2021 16:04
James___
★★★★★
(5118)
With graphite, it forms because of Van Der Waal bonds. This creates a layered structure. With atmospheric gasses, a Van Der Waal bond helps to determine the volume of gasses. This is because the stronger the bond, the closer gas molecules will be to each other.
To show the math, if
P =nRT/V-nb -a(n/v)^2, then the a(n/v)^2 shows the attractive potential of gasses.
With the V - nb, it shows volume - Avagrado's number times the size of the molecule.
Basically, nb is the densest the gasses can be as a gas and V(olume) would be gasses that have a lower temperature. Basically as gasses expand, most will cool.
And I think everyone in here knows that KE = 3/2kT can also be expressed as PV = nRT
And P = nRT/V is the same thing as PV = nRT. I know you guys are learning this.

Edited on 17-04-2021 16:06
17-04-2021 21:08
IBdaMannProfile picture★★★★★
(10017)
James___ wrote: They need both a face palm and a sadly shaking head for emojis.

Yes "they" do need such an emoji ... especially for those times that someone claims that work is mass * distance. I will make that emoji available.

James___ wrote: work is mass * distance.




James___ wrote: If a 1kg weight



Kilograms are units of mass, not of weight.

One more time:

Work = Force * Distance ... and Force = Mass * Acceleration

Ergo

Energy = Work = Mass * Acceleration * Distance

Power = Energy / Time = Work / Time


By the way, the emoji I presented above is my repair job on this emoji on tenor.com:



You will notice that it is intentionally marred (part of the face is annoyingly blocked for several frames). This is done to prevent people from using it. One has to wonder what the point was of creating it and of putting it on the internet in the first place.


17-04-2021 22:18
James___
★★★★★
(5118)
IBdaMann wrote:

Kilograms are units of mass, not of weight.



?
You really don't know this, do you? 1 liter of water defines what 1 kilogram is. Mass is relative to the weight that gravity allows for at sea level.
17-04-2021 23:36
Into the NightProfile picture★★★★★
(16138)
James___ wrote:
IBdaMann wrote:

Kilograms are units of mass, not of weight.



?
You really don't know this, do you? 1 liter of water defines what 1 kilogram is. Mass is relative to the weight that gravity allows for at sea level.


No. Mass is not weight.


The Parrot Killer

Debunked in my sig. - tmiddles

Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit

nuclear powered ships do not require nuclear fuel. - Swan
18-04-2021 00:35
James___
★★★★★
(5118)
Into the Night wrote:
James___ wrote:
IBdaMann wrote:

Kilograms are units of mass, not of weight.



?
You really don't know this, do you? 1 liter of water defines what 1 kilogram is. Mass is relative to the weight that gravity allows for at sea level.


No. Mass is not weight.



Do we really need to act this stupid? A volume/mass of 1 liter of water at sea level = 1 kilogram. If we were discussing mass then it should be an atomic mass.
Then we could have 8, 16 or 24. That's oxygen the element, the molecule and ozone. And their mass is relative to the average of 2. This is
1.67262 × 10^-27 kilograms + 1.67493 × 10^−27 kg divided by 2 = 1,67508^-27.
You see where this is going, right? Then multiply by 4, 8 and 12 and you have the mass of those 3 items. In kilograms which is mass. But because of gravity, it is also relative to weight because without mass, there is no weight.
Kind of why we are back to 1,000 cm^3 of water has both the mass and the weight of 1 kilogram. I think I made it easy enough to understand. It is rather a basic thought how gravity and mass are relative to one another.

Edited on 18-04-2021 00:39
18-04-2021 01:19
James___
★★★★★
(5118)
In your defense ITN, discussing atomic mass is getting into nuclear physics.


p.s., if you don't get it ITN, if I didn't like you, I wouldn't be mentioning this.

Edited on 18-04-2021 01:36
18-04-2021 01:54
HarveyH55Profile picture★★★★★
(3658)
James___ wrote:
IBdaMann wrote:

Kilograms are units of mass, not of weight.



?
You really don't know this, do you? 1 liter of water defines what 1 kilogram is. Mass is relative to the weight that gravity allows for at sea level.


But the seal level keeps rising... Least that's what I heard.
18-04-2021 02:10
James___
★★★★★
(5118)
HarveyH55 wrote:
James___ wrote:
IBdaMann wrote:

Kilograms are units of mass, not of weight.



?
You really don't know this, do you? 1 liter of water defines what 1 kilogram is. Mass is relative to the weight that gravity allows for at sea level.


But the seal level keeps rising... Least that's what I heard.



It is. I'm not sure that is a problem.
https://www.youtube.com/watch?v=3Ewy7UIqCng
Edited on 18-04-2021 02:14
18-04-2021 08:26
Into the NightProfile picture★★★★★
(16138)
James___ wrote:
Into the Night wrote:
James___ wrote:
IBdaMann wrote:

Kilograms are units of mass, not of weight.



?
You really don't know this, do you? 1 liter of water defines what 1 kilogram is. Mass is relative to the weight that gravity allows for at sea level.


No. Mass is not weight.



Do we really need to act this stupid?

Apparently you do.
James___ wrote:
A volume/mass of 1 liter of water at sea level = 1 kilogram.

Nope. Mass it not weight.
James___ wrote:
If we were discussing mass then it should be an atomic mass.

Makes no difference. Mass is not weight.


The Parrot Killer

Debunked in my sig. - tmiddles

Google keeps track of paranoid talk and i'm not on their list. I've been evaluated and certified. - keepit

nuclear powered ships do not require nuclear fuel. - Swan




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