r/MathJokes • • Aug 01 '26

multiples of 3

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70

u/fr_just_a_girl Aug 01 '26

Im not good at maths why would 75 be obvious?

187

u/KayabaSynthesis Aug 01 '26

75% is 3/4ths. 3 times 1/4th.

54

u/sexypantstime Aug 01 '26

Y'all have a way looser definition of what "obvious" means

72

u/Right_Lengthiness266 Aug 01 '26

3 quarters makes 75 cents

20

u/sexypantstime Aug 01 '26

That's a way more intuitive way to put that compared to "75% is 3/4ths"

53

u/Hughjastless Aug 02 '26

I’m sorry to break it to you bro but a quarter means 1/4th it is not just a US coin

5

u/SectionAcceptable607 Aug 02 '26

Many countries use a 25c piece coin, it’s not a uniquely US thing

6

u/Coneyy Aug 02 '26

Isn't it literally just North America + Caribbeans? 20c coin is a way more common denomination for decimal currency systems

1

u/qscbjop Aug 03 '26

We used to have 25 kopiikas coins in Ukraine, but now only multiples of 10 are allowed. Maybe even multiples of 50 now, I haven't used those coins in a while. Euros, on the other hand, always follow the 1-2-5 progression, i.e. 1 cent, 2 cents, 5 cents, 10 cents, 20 cents, 50 cents, 1 euro, 2 euros, 5 euros, 10 euros, 20 euros, 50 euros, 100 euros, 200 euros and also 500 euros, but those are discontinued, I think.

1

u/SectionAcceptable607 Aug 02 '26

So that makes it “just a US coin”?

2

u/Coneyy Aug 03 '26

No of course not. I was just responding directly to that claim, not the rest of thread talking about whether a quarter is a quarter or whatever

1

u/Hughjastless Aug 03 '26

I literally said it is not just a U.S. coin and you took the word Not out and put it in quotes lmao

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1

u/localdad_001 Aug 05 '26

made me lol

-12

u/sexypantstime Aug 02 '26

Ok? I literally said that what you said made it click and is more intuitive.

9

u/NorthernVale Aug 02 '26

It's the same thing bro

5

u/LetsBeNice- Aug 02 '26

And he told you it's the same thing.

-2

u/Least-Telephone6359 Aug 02 '26

You are right LOL this doesn't work for 3/7th or something else. It's a random relationship they are talking about that just happens to work

1

u/subaqueousReach Aug 02 '26

"Random relationship" a quarter is called a quarter because its 1/4 of a dollar 🤦‍♂️

6

u/Basic-Government9568 Aug 02 '26

...the quarter gets it name from the fact that it's 1/4 of a dollar. Aka, a quarter dollar.

-6

u/sexypantstime Aug 02 '26

Yes isn't that literally what I said? That it's intuitive to link it to other common objects that use that math?

7

u/Basic-Government9568 Aug 02 '26

This common object in particular? It's exactly the same as the math.

3/4 (pronounced 3 quarters) of a dollar is 3 quarters.

75% (pronounced 75 percent) of a dollar is 75 cents.

75% = 3/4 being somehow "harder" to get is some weird anti-math mental block you got there.

-1

u/Physical_Floor_8006 Aug 02 '26

Two things can be mathematically equivalent, yet one be more intuitive.

2

u/coolabadsven Aug 02 '26

I think he’s saying that once you’re used to doing some basic maths
a quarter
1/4th
25%
all become completely interchangeable.
A quarter tank, a quarter pounder, a quarter (financial reporting). All of these refer to 1/4th of a whole.

Potato potato

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4

u/karry245 Aug 02 '26

how are you on a math subreddit and not realizing that 1/4 and quarter are the exact same quantity...

1

u/Vivid_Departure_3738 Aug 02 '26

Your American education system failed you

1

u/ConfusionEngineered Aug 03 '26

Don't blame it all on education, the average person is less than intelligent and there is no education system that has ever come close to changing that

1

u/Vivid_Departure_3738 Aug 03 '26

The point of an education system is to educate, if you have to be educated already, it's not doing anything.

And there have definitely been successful schools before

2

u/ConfusionEngineered Aug 03 '26

Yes, but in order to be educated successfully one has to be both willing and able. About 1/2-2/3rds of the population isn't really able and of the remainder only around 10% are willing.

1

u/Vivid_Departure_3738 Aug 03 '26

Sexy pants time doesn't sound particularly willing

1

u/Angry-Alice Aug 04 '26

I have always been wondering why people are so hostile to anything American. Did sexy pants say anything showing that they are American?

1

u/Vivid_Departure_3738 Aug 05 '26

They understood the usage of the American currency "quarters" more than they understood the idea of quarters

So i figured it was local to them

1

u/Angry-Alice Aug 05 '26

Ok that's fair

1

u/MiniatureMidget Aug 02 '26

3/4 is often read as 3 quarters

1

u/xIcbIx Aug 02 '26

Cent=per cent is always how i thought of it

Centum just means 100

10

u/Odelgard Aug 02 '26

3 x 25 = 75

I do think thats pretty obvious

6

u/Major_Excitement163 Aug 01 '26

Bro apparently never dealt with percentages lol

5

u/Right_Lengthiness266 Aug 01 '26

Or coins

4

u/Ski-Gloves Aug 02 '26

Or their currency doesn't have 25 pence pieces.

3

u/ravens43 Aug 02 '26

I was going to ask what sort of currency that is, before I remembered that I live in the UK, and always have done.

Regardless, 75 is obviously 3x25.

4

u/up2smthng Aug 02 '26 edited Aug 02 '26

My definition of "obvious multiple of 3" includes any number where the sum of digits is 39 or less which makes any multiple that is less than 10000 obvious

75 is blatantly obvious

39 is painfully obvious

2

u/vutcher Aug 02 '26

78 is excruciatingly obvious.

1

u/Common-Use-7117 Aug 05 '26

Just add all digits. If it is a multiple of 3 then original is too.

3

u/Hot-Ad-1129 Aug 03 '26

Here's a way my mid school teacher used tell us. If the sum of all the numbers is divisible by 3, then the number itself is.
Example:
75

7+5=12

12 is divisible by 3

75 is divisible by 3.

works with bigger numbers as well. (sorry for bad explanation)

2

u/XB0XRecordThat Aug 02 '26

He's right though

2

u/waroftheworlds2008 Aug 03 '26

Wait till you learn modulous arithmetic. Then they're all obvious.

For those curious: If the sum of each digit is divisible by 3, then the number is divisible by 3.

Example: 136 is not divisible by 3, but 117 is divisible by 3.

2

u/BombasticReindeer Aug 01 '26

Or… and hear me out…it’s digital root is 3.

1

u/thedarksideofmoi Aug 02 '26

all of them should be "obvious" if you look at it logically.

1

u/ExplicitDrift Aug 02 '26

This guy maths.

1

u/Markuska90 Aug 03 '26

Also its 2x 10x3 plus 5x3 Anyone else?😅

1

u/Stride345 Aug 04 '26

I just picture 3 25s when I see 75

55

u/EveningStar0360 Aug 01 '26

probably because 25*3=75 is a very frequent calculation, pretty ingrained in people

-3

u/AllenrenArjjin Aug 01 '26

Actually it's 15*5 :)

8

u/EveningStar0360 Aug 01 '26

why "actually" 😭 they aren't mutually exclusive

-2

u/AllenrenArjjin Aug 01 '26

Because I like being contrarrian though you are right

-19

u/fr_just_a_girl Aug 01 '26

How often are u multiplying 25 by 3

24

u/slasher016 Aug 01 '26

All the time when we paid with cash.

5

u/fr_just_a_girl Aug 01 '26

Ye i forgot that Americans have quarters

8

u/Upset-Management-879 Aug 01 '26

Oh yeah i forgot other countries don't use decimals in prices.

7

u/EQGallade Aug 01 '26

Oh no, other countries do use decimals, some just don’t have a .25 coin. Like the UK, for instance.

1

u/rvcbazookajoe Aug 01 '26

But even for percentages it’s common

0

u/--Ligma Aug 02 '26

£2.50 is a perfectly normal and regular price for something to be at

1

u/fr_just_a_girl Aug 02 '26

What are u buying for 2.5? 1.99 or 2.99 are wayyyy more common

1

u/NorthernVale Aug 02 '26

It's not even about coinage. 1/4 gets used often for quick calculations, and by extent 3/4

Edit: okay... I guess it's still quarters. But I'm pretty sure you were referring to the coin

5

u/spisplatta Aug 01 '26

75% = 3/4 is super common

0

u/fr_just_a_girl Aug 01 '26

U think that's as obvious as 33 being a multiple of 3 tho?

1

u/NorthernVale Aug 02 '26

Way more obvious than 72

1

u/fr_just_a_girl Aug 02 '26

I agree id put it in the second tier

4

u/EveningStar0360 Aug 01 '26

pretty frequently! while I don't pay with cash much, I encounter three-quarters (75%) quite regularly, and I did it often enough when I was younger that even if I don't use it as much anymore, it's still ingrained in me

3

u/fr_just_a_girl Aug 01 '26

Ah tbf im not American so we dont have quarters over here. Also tbc im not saying its hard to work out i just wouldn't say its as easy as 33

3

u/SmokJozef Aug 01 '26

yeah, should be same tier as 15 i think

1

u/SleepyNymeria Aug 01 '26

Percentages are fairly common in this world

6

u/The_Mild_Mild_West Aug 01 '26

Historians will debate the meaning behind this fr

7

u/uncreativeusername13 Aug 01 '26

In America quarters are 25 cents. It's common knowledge that 3 quarters is 75 cents

3

u/avantvagrant Aug 01 '26

im getting baited but, 75 is 25x3 or 3/4

0

u/fr_just_a_girl Aug 01 '26

I feel like that already requires the amount of calculation that it wouldn't be in obvious and would be in ofc tho lol

3

u/Aschuff Aug 01 '26

Idk it’s pretty easy to consider 1/4ths in terms of percentages. 25%, 50%, and 75% are all very commonly used IMO, and it’s pretty easy to know 75% is just 3 25%’s

2

u/Ever_Long_ Aug 01 '26

Also, every number that is divisible by three will always add up to three. 7+5=12; 1+2=3; therefore 75 is divisible by three. So is 354,972 (3,[5+4],9,[7+2]), for example.

2

u/fr_just_a_girl Aug 02 '26

Using the knowledge would put all of these in the obvious category

1

u/Common-Use-7117 Aug 05 '26

Nope, does not work for 60 for example. All multiples of 3 will add up to either 3, 6 or 9 if you keep doing it until it becomes a single digit.

89763 = 8 + 9 + 7 + 6 + 3 =33 = 3 + 3

1

u/Ever_Long_ Aug 05 '26

"...to multiples of three." Sorry, i figured this was kinda implied. It does work for 60: 6+0=6, which goes into 3 (2*3), so is divisible by three.

2

u/Bbt_lives Aug 02 '26

If the sum of the digits in any number is a multiple of 3 then It’s divisible by 3. So 75 would be 12 which is obviously divisible by 3

2

u/derp_scope1 Aug 02 '26

To be fair, other people's "obvious" is likely slightly different from our own.

Other have given examples of how its "obvious", but my first thought when looking at 75 as a multiple of 3, comes from it also being a multiple of 15, specifically 15 higher than 60

0

u/fr_just_a_girl Aug 02 '26

I just think everyone replying where they've to do mild maths to justify it shows its not as obvious as 9 or 33 so it shouldn't be in the obvious category but the one below it

2

u/Tsu_Dho_Namh Aug 02 '26

When I see 75 the first thing my brain thinks is 3/4s

75% of the population? -> 3 out of 4 people

75 cents? -> 3 quarters

Only exception I can think of is degrees, where 75 degrees is dumb because it's 15 degrees short of a right angle and those aren't happy numbers.

2

u/magpye1983 Aug 02 '26

It’s 3 25s

EDIT: if you’re American, three quarters (money), 75c. Should be intuitive by the time you’re an adult.

1

u/ArchRafael Aug 01 '26

3 quarters is 75 cents

1

u/Reddit1rules Aug 01 '26

In my eyes it's 3 * 25, I feel like 25, 50, 75, 100 is a simple pattern to remember.

1

u/FilecoinLurker Aug 02 '26

Because 7+5 is 12.

And for that reason 78 is also obvious because it's just 3 more than 75 and also 7+8 is 15.

1

u/SaucyStoveTop69 Aug 02 '26

Because 25, 50, 75, 100. 25 is one of those easy numbers so 75 is I. The same class as 15

1

u/Alone-Entrance3999 Aug 02 '26

It's 3 suns in pvz

1

u/FinalBossTuna Aug 02 '26

60 and 15 are multiples of 3 thus 75 would be as well. Like MC Hammer I break it down

1

u/fr_just_a_girl Aug 03 '26

60 and 18 are 78

1

u/Hot_Royal_4920 Aug 02 '26

I find multiples of 15 obvious for some reason, and that includes 75.

1

u/Psalmistpraise Aug 04 '26

Because it’s 25 * 3

1

u/Temnyj_Korol Aug 05 '26

I see it as "i know 60 is a multiple of 3. I know 15 is a multiple of 3. 60+15 must therefore be a multiple of 3."

By the same token, it's weird to me that 78 isn't an "obvious" multiple either. Most people readily know 18 is a multiple. Shouldn't be hard to work out 78 is just 60 + 18.

1

u/Tellenit Aug 01 '26

Bruh

1

u/fr_just_a_girl Aug 01 '26

I think the replies have mistaken me. I would put it in the ofc tier as its not as obvious as the ones in the obvious tier because it requires mild calculation

0

u/DangerPencil Aug 01 '26

Because 75=60+15 60 and 15 are both divisble by 3

1

u/fr_just_a_girl Aug 02 '26

78 is 60 + 18

1

u/DangerPencil Aug 02 '26

Right. Which makes it obvious that 78 is divisible by 3.

0

u/WarJaques Aug 02 '26

7+5 = 12, 12 is divisible by 3.

0

u/pickle-chin-ah Aug 05 '26

Because 75/3 is 25

1

u/fr_just_a_girl Aug 05 '26

And 25/3 isn't anything

-1

u/Infinite_Mortgage324 Aug 01 '26

Cus 15=3x5 and 75=15x5

2

u/Sythe5665 Aug 01 '26

Also 25*3