/r/theydidthemath

Photograph via snooOG

And they said math has no real world applications

Submission Rules

  1. Proper title tags are required for all posts or it will be removed! The tags accepted are at the end of the sidebar down there.

  2. State clearly what is being or what you want calculated in the title. [Request] posts must have a calculable answer; otherwise, they will be removed.

  3. Give credit where credit is due—include the user who made the calculations in any post you submit: ex. "[RDTM] /u/FragTheWhale calculates...".

  4. For easy and quick math results (ex. How many feet are in a mile?) use Wolfram|Alpha™. Posts containing "simple math" will be removed, as well as requests whose answers are easily searchable online, and any other post at the moderators' discretion. For more abstract math, try /r/math or /r/learnmath.

  5. Posts which seem to be asking for help on homework will be removed. Try /r/homeworkhelp or /r/cheatatmathhomework instead.

Comment Rules

  1. This subreddit has a zero-tolerance policy for hateful or unnecessary language. There is no warning for hate speech of any kind. Rule breaking posts/comments will have a temporary ban that will serve as a first offense "warning". Repeat or egregious offenders will be banned permanently. Reddit's site-wide rules still apply here. Also, don't be a dick.

  2. Do not submit top-level comments in [Request] posts that are not an attempt at an answer or a request for clarification. Jokes or off-topic top-level comments will be removed.

  3. When answering [Request] posts, please cite reputable sources to defend any evidence that cannot be proven using your own math.

Report any spam/rule breaking posts to the mods with the report button. Be sure to include the reason for your report!


LaTeX and subscripts/superscripts

[; e^{\pi i} + 1 = 0 ;]

Superscripts and subscripts are supported in this subreddit, and LaTeX is used here as well. If the above equation looks like garbled code, or for information on how to display subscripts and superscripts, check our wiki page.


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TAGS!

We require title tags. Here are the tags we accept and what they are for. Please keep them at the start of your post.

  • [Request] - Asking the /r/theydidthemath community to do the math for you!

  • [Self] - You did the math and want to share it!

  • [RDTM] - "Reddit Did The Math", linking to a comment or post on Reddit where someone else does the math!

  • [Off-Site] - Use when linking to any site, including Imgur, that is not reddit.com.

  • [Meta] - Non-math posts regarding the subreddit itself. Don't use this unless you really have to.


Sidebar image from Randall Monroe's xkcd

  1. Browse by tag ▸
  2. Request
  3. Non-Request
  4. Self
  5. RDTM
  6. Off-Site

/r/theydidthemath

1,605,034 Subscribers

0

[REQUEST] Trying to calculate the speed my car was hit at.

Hi all. An approximately 5,000lb 2012 Chevy Silverado (truck) plowed into the front left side of my approximately 3,000lb 2021 Hyundai Sonata (sedan) (see image). I was at a stop sign, stopped, intending to turn left, when all of a sudden my car was hit by this truck. The road the truck was on has a speed limit of 45mph, but it seemed like the truck was going much faster than that since the front of my car was completely ripped off, was spun around to the right, and wound up in a ditch on the other side of the road. The truck withstood some front damage and crashed himself into an electric pole. Both vehicles were totaled. I know it might be a bit difficult to calculate but I provided as much info as possible. Thank you in advance for the help!

3 Comments
2024/12/01
19:44 UTC

2

[Request] How many star systems will be flung into deep space as a result of this?

2 Comments
2024/12/01
19:17 UTC

1

[Request] Can anyone explain this equation to me?

Chatgpt hit my with this equation, I asked it to explain it and the explanation did not help my understand it at all

2 Comments
2024/12/01
18:49 UTC

7

[Self] It's more common than you'd think! Happens every 7 years on average.

2020 started on a Wednesday, and we know that every year "adds 1 day" i.e. 2021 will then start on a Thursday. A leap year "adds" 2 to the subsequent year, as the extra day is in February. Using this, we get:

2020: Wednesday (+2) 2021: (+1=3) 2022: (+1=4) 2023: (+1=5) 2024: (+2=7) 7 reached by Feb 2024! So now, 2025: Wednesday (+1) 2026, 2027, 2028, 2029, 2030: (+1+1+2+1+1=7) 2031: Wednesday (+1) 2032, 2033, 2034, 2035, 2036: (+2+1+1+1+2=8) The leap year caused jumping over, so we now have to continue till we reach the next multiple of 7, 14. 2037, 2038, 2039, 2040, 2041: (+1+1+1+2+1=14) 2042: Wednesday! 2043, 2044, 2045, 2046, 2047: (+1+2+1+1+1=7) 2048: Wednesday!

As we have reached a leap year again, with cycle length 28 divisible by 4, the cycle will now repeat, (5, 6, 11, 6).

1 Comment
2024/12/01
18:01 UTC

13

[Request] What percentage of the world finds this meme relatable? In other words, how many people on earth are awaiting knee surgery in 24 hours from now (or less)?

6 Comments
2024/12/01
17:59 UTC

105

[request] If the nail is solid not hollow, what could be the weight?

26 Comments
2024/12/01
17:57 UTC

0

[Request] Is that actually 22 Factorial? (Sry I'm dumb)

15 Comments
2024/12/01
17:49 UTC

1

[Request] How many spoons were there in Canada in 1995?

2 Comments
2024/12/01
17:30 UTC

3

[Request] How much would a 1 second black hole destroy

If a blackhole appeared at sea level on earth for exactly 1 second before disappearing how much of the planet would be destroyed?

17 Comments
2024/12/01
17:24 UTC

1

[Request] how fast would the wind need to be to run in the cartoon panic run?

Like arms and upper body leaning back flailing around while they run. How much wind would be required to not just fall on their backs?

1 Comment
2024/12/01
16:58 UTC

1

[request] How many tones of copper did this man steal before being caught?

A man in China donated 550K USD to a Chinese streamer, 316K of this was gained through over 40 copper thefts since May. How much copper is this realistically?

2 Comments
2024/12/01
16:40 UTC

101

[Request] How big would God be?

6 Comments
2024/12/01
16:26 UTC

0

[Request] How fast would Santa have to move to actually deliver presents to every house?

Assuming half the households in the world celebrate Christmas, how quickly would Santa have to move to get in and out of all of them in one 8-hour night?

3 Comments
2024/12/01
15:10 UTC

0

[Request] Is a lawnmower is more effective than a rake ? Breakdown in (fuel) energy consumed & time required (or so).

19 Comments
2024/12/01
14:48 UTC

4

[Request] How loud would that fart have to be to shatter the glass, or how much gas would he have to release to blow it out?

5 Comments
2024/12/01
14:35 UTC

40

[Request] How fast would a spinosaurus have to run to walk on water like the basilisk?

7 Comments
2024/12/01
14:08 UTC

1

[Request] How long will my battery last?

How long will my battery last?

I’m using a camera that is 5v 2a (Ubiquiti g3 instant). The battery and solar panel I’m looking at getting is 5200mah battery with an 800mah panel. How long will the camera stay powered on during a clear day in East Tennessee with unobstructed sunlight starting at 10am and lasting until 7pm?

I have a camera. I’m buying a bird house with a camera for super cheap. It has the onboard battery and solar charger. I’m going to swap the camera with my current one. I may upgrade the battery and or solar panel later, but this will get me started. TIA!

1 Comment
2024/12/01
13:59 UTC

3

[Request] How fast would Rita Repulsa’s staff be traveling, to reach Angel Grove from the Moon?

In the old Might Morphin’ Power Rangers show, Rita Repulsa used to throw her magic wand from her moon base, down to Angel Grove to make her “monster grow”. Assuming the wand is roughly 6’ in length, weighs about 2.5kg, and is made from an unknown “magic alloy” that could survive entry into Earth’s atmosphere, and that Angel Grove is in Southern California, how fast would the wand have to be traveling, to make the journey in the roughly 4 secs it shows? Also what kind of impact would that have?

2 Comments
2024/12/01
13:55 UTC

23

[Request] Are there even enough atoms in there to fit at least part of 22! strawberries?

11 Comments
2024/12/01
13:44 UTC

5

[REQUEST] How big would be full destruction radius of tsar bomba if it was detonated directly on ground and how far away would go radius of any noticable destruction?

7 Comments
2024/12/01
12:38 UTC

1,491

[Request] How many paper towel roles will be required to suck up an entire waterfall?

62 Comments
2024/12/01
09:49 UTC

1

[Request] could someone help me with the math?

Hey guyss

Im facing a dilemma and wanted to see if I could use math to solve it.

I wanted to travel during new years, I havent applied for the visa yet but Im supposed to this week, and the response is supposed to come the week after.

The plane ticket is around 51,000 EGP, and the cancellation fee is around 10,000 EGP. That cancellation fee is a lot of money for me to just lose so should I buy the plane ticket now and worst case scenario pay the cancellation fee or should I apply for the visa and monitor the plane ticket price, noting that it could jump to whatever number (not necessarily gradually).

Is there a math formula to help me decide?

Thank you!

3 Comments
2024/12/01
08:28 UTC

52

[Request] find the missing number

Please, find the missing number so I can get a good night sleep. 😅

12 Comments
2024/12/01
07:45 UTC

0

[Request] Im not the best at math, but whats the equivalent of the eruption today compared to modern weapons? (Nukes?)

4 Comments
2024/12/01
07:20 UTC

84

[REQUEST] How far would this actually be?

5 Comments
2024/12/01
05:50 UTC

2

[Request]if you got all the water in all the oceans, turned it into 2 equal sized cubes, then teleported it into space, with one cube inside earths shadow and one cube outside earths shadow, how long would it take for each cube to freeze?

(did i use too many commas? i feel like i use too many commas too much)

5 Comments
2024/12/01
03:22 UTC

0

[Request] What is the mathematically average ammount of fingers on both hands

things like polydactyly exist that would bring it up but also Oligodactyly people. i want a average rounded to 3 decimals AT MOST, counting since birth

18 Comments
2024/12/01
03:01 UTC

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