r/theydidthemath 50m ago

[Request] How much dirt would it take to fill in this area?

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r/theydidthemath 1h ago

[Request] I Drank My Parents’ Vodka

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[Request] Ok no I didn’t, I’m 30, but I had a math thought. Let’s say I broke into my parents vodka, I think “I can drink 10% of the vodka and then fill the rest with water, mix it all up, and they’ll never know.” I do this, but the next time I think the same thing, “I’ll drink 10%, fill it up with water, and they’ll never know.” Of course, I’m a big dumb dumb and it will taste less and less of vodka. Assuming the water and vodka blended perfectly (aren’t immiscible) at water point does it all become water? Or, does it? Would this be logarithmic?

Moreover (although I guess this is sort of a chemistry question), let’s say they keep their 80 proof (40% alcohol) in the freezer, at what point in my taking of their vodka, does that liquid freeze?


r/theydidthemath 1h ago

[RDTM] On r/shitposting

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r/theydidthemath 1h ago

[Request] How many names on this list given the length?

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r/theydidthemath 2h ago

[Request] Tower is 650 meters tall. It takes 7 seconds to form one regret. How many things can you regret if you fall?

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24 Upvotes

r/theydidthemath 2h ago

[Request] 2 bullets hit each otherin center but one is way smaller? (see link)

0 Upvotes

Ye I know it's a movie but what will actually happen(hope you cna use links here):
https://www.youtube.com/shorts/EtS7FQZ4Lcg

way smaller bullet hit centrally bigger bullet (I assume they have same speed)


r/theydidthemath 3h ago

[REQUEST] At what distance from earth would the moon appear to have the same size as the earth

1 Upvotes

r/theydidthemath 4h ago

[REQUEST] In Russia, Google LLC has 2 duodecillion debt. As I heard, even if we make exact copy of our planet made of 5000 rubles banknotes, it wouldn't be enough. Is it true?

0 Upvotes

Edit: 2 duodecillion in rubles. And also, it's debt only to TV channels, which I'm interested in.


r/theydidthemath 4h ago

[Request] Saw this on twitter. I was thinking it was 2, but not sure.

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221 Upvotes

r/theydidthemath 5h ago

[Self] Why your $999 Apple MacBook Air is about to cost $1600

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918 Upvotes

Selling Price = (CoGS * (1 + Tariff%)) / (1 - Margin)


r/theydidthemath 5h ago

[Request]I thought that 12.75% of a dollar is $0.1275,but I'm not sure anymore,can someone check this please?

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0 Upvotes

r/theydidthemath 5h ago

[Request] what are the odds?

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0 Upvotes

r/theydidthemath 6h ago

[Request] how long this video is going to take

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2 Upvotes

r/theydidthemath 7h ago

[REQUEST] How long would it take for an average island to fall from sea level to the center of the Earth?

1 Upvotes

I was reading a fiction book (One Piece), and a certain situation that happens WAY LATE into the story intrigued me, and thinking about what could have happened led me to make this weird question.

If there was a hole big enough for the mass and area of an entire island (average) to fall through to the center of the Earth, considering drag in either water or air or magma, how long would it take? Because whenever I search it up, the quickest answer always discounts any resistance from any fluid at all, and example results that do take it into account wouldn't translate well into this particular question.


r/theydidthemath 7h ago

[Request] Did Pokémon accidentally reinvent the Monty Hall problem?

3 Upvotes

The Pokémon TCG Pocket game has a mechanic where you are shown 5 cards face down, in which there is usually only one desirable card, and let you pick one at random to keep

That's all well-and-good, but recently they added an event where you get to "peak" at one of the cards before you make your choice.

Now - if the one you peak is correct, you can just pick it, so that math ends there. However, if the card you pick is incorrect, does the logic of the Monty Hall problem apply?

I, and I think most others, mentally decide a card to pick before it's even time (I always pick the bottom right). If I reveal a different card and it's incorrect, is it statistically probable for me to forsake my mental guess and pick one of the other 3 cards? This feels wrong, the game didn't know that was my choice, it feels like it should now be no less likely than the other 3 cards.

However, wouldn't the logic of the Monty Hall problem apply to this, and say it is incorrect? That, logically speaking, my initial probability doesn't change from 1/5 despite the fact another one was eliminate (this is, to be clear, under the theoretical that the 'peaked' card is wrong, as the peaked card being correct ends the scenario). If there was a 1/5 chance my initial guess was correct, there is a 4/5 chance it was wrong. If a card is revealed, there is still a 4/5 chance I was initially wrong, but if there are only 3 possible cards to switch to, they split that 4/5 3-ways, making them each 26.66% likely to be correct (as opposed to my 20%), no?

This is my way of understanding the Monty Hall problem but practically speaking I don't feel like that can be incorrect? The game doesn't even know my initial 'mental' pick, so how could there be a statistical difference if I choose it or swap it.

And if any of the 3 swaps are really 26.66% likely in that scenario, wouldn't that mean mentally envisioning one and then swapping it is actually (very slightly) more likely than peaking at one at random and then picking one of the remaining 4 (25%)? Again, in both these scenarios just not factoring in the possibility that the peak is correct, which should apply to both scenarios equally anyway and not change the end result.

I don't know what the flaw in my logic is but I can't imagine that 26.66% correct. If the 1/5 chance the "peaked" card was incorrect is distributed to all 4 cards then it's 25%, but wouldn't that mean the Monty Hall problem results in a 50% chance instead of a 66% chance?

Can anyone help me break down the probability in this scenario? Is there a flaw in my understanding of the probabiltiy or do you really increase your chances by mentally choosing one and then refusing to take it?


r/theydidthemath 8h ago

[REQUEST] Want to Split 10 People Into 3 Groups 3 Times

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10 Upvotes

Firstly, please excuse the odd numbering system - it matches up to a spreadsheet that I am using!

I am going away on a golf trip in a week or so's time. There are ten golfers and we are playing three rounds. For each round, we need two groups of three, and one group of four.

I would like to organise the groups in such a way as to ensure that we can all play with as many different golfers as possible. My best current attempt is in the image. I was hoping that somebody might be able to tell me a) whether there is a better solution and b) if there is, either what the solution is, or how best to go about calculating it.

I have attempted to use websites that separate into groups using simpler parameters, but they don't give me anything better than what I have got thus far.

Thanks in advance!


r/theydidthemath 9h ago

[Request] What's his speed?

210 Upvotes

r/theydidthemath 9h ago

[Request] How far away could you see a space elevator from the Earth's surface?

0 Upvotes

As the title says.

Imagine you had some structure, like a tower or space elevator that extended into space, well beyond the atmosphere (ignoring the difficulties of creating such as structure).

If you were standing on the Earth's surface, and assuming relatively level terrain (we'll say approximately "at sea level"), how far away would you be able to be and still see at least a glimpse of this structure?

Bonus question (not really math, more optics/physics): What would the "top" of the tower look like at the point where you can no longer see it going up? Would it just kind of fade to a "vanishing point", have some clear cut-off, or basically fade as if someone put a transparent gradient at the top?

Thanks.


r/theydidthemath 10h ago

[REQUEST] Can skydivers in a wing suit fly up?

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384 Upvotes

I don’t mean like flapping their wings but - theoretically - could a wing suit skydiver find some perfect slope that works where they can gain altitude to a point of stall and land safely without a parachute? Alternatively could a glider do this?


r/theydidthemath 11h ago

[REQUEST] How many FPM does Daredevil hear in the city? farts per minute.

0 Upvotes

Daredevil can hear a gun cock from blocks away.

Is he hearing hundreds of farts per minute all day long?


r/theydidthemath 12h ago

[Request] Student aid anti-trust suit

1 Upvotes

People are speculating on the expected payments for a huge anti-trust suit against many schools, who colluded to cook the books on financial aid calculations.

So the question is. If there is 200M dollars available, and 200k POSSIBLE claimants, and the claim amount varies by the number of years attended for undergrad... what is the expected claim amount if every possible person submits a claim... for the classes of people who attended for 1, 2, 3, and 4 years of the relevant window.

I think it is a pretty interesting question.


r/theydidthemath 12h ago

[Request] How fast is "385 bald eagle-hours per NYC to London"?

0 Upvotes

i'm assuming that they meant the flight time between the cities but can't do thing myself cuz i'm buzy laughing my butt off


r/theydidthemath 16h ago

[Request] What number can be expressed as a 1 with some amount of zeroes behind it that is larger than just 1 in the most possible numerical bases?

1 Upvotes

r/theydidthemath 16h ago

69 kilograms of computer storage would weight around 8600000000000000000 terabytes. [Self]

0 Upvotes

The weight of each bit is just one electron and one electron weight around 9.1*10-31.

(69kg)/((9.110-31)kg/electron)=7.581031 electrons

This is also the number of bits, to convert to bytes. We just divide by 8 and get

9.481030 bytes or 7.8 million yottabytes(8.61018 terabytes).

This is just an approximation and I was being generous in the calculations, please correct me if i got something wrong, it is very possible since I am just a child and English is not my first language.


r/theydidthemath 17h ago

[Off-Site] He just... dumped the math like that... | truckloads to fill a hole

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1 Upvotes