You have 30 seconds. Viral riddle from The 1% Club

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  • Опубликовано: 17 дек 2024

Комментарии • 144

  • @Jerry_Fried
    @Jerry_Fried 7 часов назад +91

    I think the most efficient way to think about it is not in terms of 99% vs 98%. It is in terms 1% vs 2%. One person equals one percent of one hundred people. The same one person equals two percent of how many people? 50. So 50 people have to leave.

    • @mdmishfaqahmed2138
      @mdmishfaqahmed2138 6 часов назад +2

      Now, how many to make it 97% 🙄

    • @Danimal.69
      @Danimal.69 6 часов назад +3

      1 / (1 + 1) = 50%
      1 / (1 + 2) = 33%
      1 / (1 + 9) = 10%
      1 / (1 + 19) = 5%
      1 / (1 + 49 ) = 2%

    • @briant7265
      @briant7265 5 часов назад +3

      My approach was:
      1? Nope. Brief thought. 50? Yup.
      Going back to do it analytically, I did what you did:
      1% = 1/100
      2% = 1/50
      Done.

    • @tedn6855
      @tedn6855 4 часа назад +3

      Not a round number at least 67 would have to leave for 3%

    • @pileb
      @pileb 3 часа назад +1

      Yeah, focus on remaining items, not on leaving ones 🙂

  • @aliasmask
    @aliasmask 7 часов назад +62

    The way I thought of it is the 1 right hander has to be 2% of the room, so total needs to be 50, so 50 left handers need to leave.

    • @ompattewar3493
      @ompattewar3493 5 часов назад +5

      This is how I got it too. Pretty straight forward.

    • @GodmanchesterGoblin
      @GodmanchesterGoblin 2 часа назад

      Yes, by considering that 1 person is 2% I got the correct answer in less than ten seconds. Maybe I should start entering game shows...

    • @HpPmL
      @HpPmL 41 минуту назад

      Did you just assume that person's laterality?

  • @MichaelSmith-fj7di
    @MichaelSmith-fj7di 7 часов назад +41

    The answer is that 50 people must leave. We know that 49/50 is equal to 98%, thus, since there are 99 people who are left-handed currently and you need 49, 50 must leave.

    • @youtubeuser1052
      @youtubeuser1052 5 часов назад +3

      Yep, it should be instantly obvious that 98/100 = 49/50 based on the obvious fact that if the numerator and denominator are both even you can reduce any fraction by dividing by two. Once you notice that, you just need the obvious fact that 99/100 left handed people means one right handed person, and therefore you just need to go from 99 left handed to 49 left handed in the room to get to the target 49/50.

  • @Stirdix
    @Stirdix 2 часа назад +3

    Intuitively, it's like trying to increase the saltiness of saltwater by removing water rather than by adding salt. Since most of saltwater is water, you have to boil off a lot of water vs. adding a small amount of salt to change the concentration.

  • @AdamRapW
    @AdamRapW 4 часа назад +4

    This question is way too sinister to be believable.

  • @iWizardzZ_x
    @iWizardzZ_x 7 часов назад +28

    Flip it, in a room of 100 people, 1% are right handed so only 1 person. To raise that to 2% 50 people must leave.

    • @mihirdhakan7042
      @mihirdhakan7042 7 часов назад

      Yep this is the best one, classic GMAT stuff kudos brother

    • @HpPmL
      @HpPmL 43 минуты назад

      It never says that the non-left-handed person is right handed. You're making assumptions.
      They could be missing both arms or identify as ambidextrous or laterality fluid.

  • @davidblack9071
    @davidblack9071 7 часов назад +5

    If you asked me if you missed one question on a 100 point test and got a 99% how many questions would there have to be to miss one question and get a 98% I would have immediately got this in less than 30 seconds. I wonder why my brain failed like this.

  • @PoppySuzumi1223
    @PoppySuzumi1223 День назад +31

    It should be easily seen that
    49/50 = 98%
    So, in order to get 98%, 100-50=50 people must left, so that the remaining one is not left-handed still remains in the room.
    Quite a logical IQ puzzle.

    • @n0dr0gs49
      @n0dr0gs49 7 часов назад +5

      There is one right handed person (1% of 100) which is 2% of 50.

    • @albertjosefsson7304
      @albertjosefsson7304 7 часов назад +1

      Yes, that person not left-handed represents a 1%, in order for that person to represent a 2%, it means his "weight" has to double. Therefore all the rest must half.
      It is pretty obvious but at first I didn't realized 😮

    • @mdmishfaqahmed2138
      @mdmishfaqahmed2138 6 часов назад

      Now you know why getting 1 percentile higher becomes so tougher and tougher as you climb higher 🙄

    • @Orrinn123
      @Orrinn123 3 часа назад

      In 30 seconds 49/50 might as well be a random number. The solution other people posted is much better imo. Which is to think out of how many people does 1 right-handed person make 2%?

  • @robheale9860
    @robheale9860 5 часов назад +3

    Interestingly if 90 lefthanded people leave the room, the percentage of lefthanded people remaining is still 90%

  • @daveincognito
    @daveincognito 5 часов назад +4

    98% of the room needs to be left-handed. You have 1 person who is (presumably) right handed. 1 is 2 percent of what number?

  • @ingiford175
    @ingiford175 7 часов назад +4

    Depends, if you are an engineer and want 98 point something, then 1 should be enough, if you want exactly 98, then 50....

    • @GodmanchesterGoblin
      @GodmanchesterGoblin 2 часа назад

      But this engineer would want the percentage to be less than 98.5%, otherwise it's still pretty much the same as 99%. 😊 One leaving would not be enough, but 34 leaving would be.

  • @daakudaddy5453
    @daakudaddy5453 6 часов назад +2

    You should have continued the graph till 99 left-handed people (Ls) left the room. While the percentage initially drops slowly from 99% to 98%, the decline sharpens till we reach 98 Ls leaving (at which point its 50% with 1 L and 1 Rleft in the room), and then drops very sharply to 0% as the last L leaves. It's kind of like the inverse of radioactive decay.

  • @SumitKumar-oz7th
    @SumitKumar-oz7th 42 минуты назад +1

    (99-x)/(100-x)=98/100
    X=50

  • @r6u356une56ney
    @r6u356une56ney 6 часов назад +3

    Damn, I saw the question in the thumbnail, and solved it in less than the time limit before I even clicked the video. Where's my cash?

  • @PhonyHomie86
    @PhonyHomie86 5 часов назад +3

    There can be a 100 people in a room and 99 don’t believe in you…

  • @mathmannix
    @mathmannix 7 часов назад +2

    Thanks, watermelon puzzle!

  • @deerh2o
    @deerh2o 5 часов назад +1

    In general, most math contest folks know that only the factors of 100 lead to an integer percentage (between 1 and 100). So if x is a factor of 100, 1/x is an integer percentage. The two highest factors of 100 are 50 and 100, leading to 2% and 1%. Focusing on the left-handers gives the puzzle it's juice, but focusing on the single right-hander leads to the quick and elegant solution.

  • @smylesg
    @smylesg 7 часов назад +1

    There are always one more person in one room than the number of left handers. That makes x/(x+1)=0.98 => x=49. So 50 of the 99 left handers must leave to get down to 49.

  • @stevemichael8458
    @stevemichael8458 7 часов назад +2

    I don't understand what is paradoxical about this. The right hander needs to be double the percentage so the total number needs to be halved. What paradox?

  • @andymanaus1077
    @andymanaus1077 6 часов назад +1

    I thought of the question in terms of the frequency of the non left handed person. 1% is equivalent to a frequency of 1 in 100. 2% is equivalent to a frequency of 1 in 50. Therefore to accomplish a state where 98% of people are left handed, 49 left handed people must be in the room.
    99 - 49 = 50

  • @spence524
    @spence524 Час назад

    The goal is 98% lefties and the number of righties is constant at 1. If we want to know about 98% lefties, that means 2% right handers. If we say X equals the total population of people then the simple equation is 1/X = 2/100. Cross multiply and solve for X. 2X = 100. X= 50. Pencil drop.

  • @ZytJans
    @ZytJans 7 часов назад +1

    98% is exactly 49/50.
    Thus, 50 left handed people should leave to reach 98%.

  • @kiritokun7474
    @kiritokun7474 7 часов назад +1

    it could be difficult to think smart live in a TV Show with a time limit.. but to see this "problem" in a chill situation makes it not even hard.. it is maybe only surprising for ppl who not think much about percentages..
    i do it often for fun or to calculate win/loss in my fav video game.. maybe thats why it was not such of a problem for me or even surprising 🤔

  • @wiggles7976
    @wiggles7976 5 часов назад

    If there is 1ppm fluoride in the water, you gotta remove a LOT of water (removing just water, not fluoride) to up the concentration, supposing you had a litre of solution. Even removing half the water still doesn't make it very fluoridated by ratio.

  • @D1g1talMess
    @D1g1talMess 7 часов назад +3

    98% = 98/100
    simplifying the fraction brings it to 49/50
    admittedly, I didn't know the answer at first, but after it was revealed, it seemed obvious

  • @quakerblacksmith1818
    @quakerblacksmith1818 Час назад

    This problem is encountered in the real world too. Oil filters have a beta rating indicating how efficiently they remove particles of a given size. To calculate the efficiency, you subtract one from the beta rating and divide it by the beta rating (beta-1/beta), so a beta 50 is 98% efficient and a beta 100 is 99% efficient.

  • @iridiam
    @iridiam 3 часа назад

    One way I like to think of it is "how many left-handers will need to stop being left-handed to get to 98%?" Obviously, that's 1, since that will give us 98 left-handers and 2 non-left-handers. Now just divide the room into 2 equally sized halves, and the solution is evident.

  • @maxhagenauer24
    @maxhagenauer24 7 часов назад

    Black Pen Red Pen did this exact problem a few days ago. (99 - x) / (100 - x) = 0.98, x = 50

  • @paparmar
    @paparmar 2 часа назад

    Given that we are dealing with exclusively whole numbers, the only possible way to have a group of under 100 people that has a subgroup that is exactly 98% of the total is 49/50. So you'd need 50 lefties to leave. In other words, if you tell me you scored 98% on a test that had less than 100 questions, I'd know you must have gotten 49/50 (OK - assuming each question was worth either zero or 1 pt., analogous to each person being either right or left handed).

  • @lagautmd
    @lagautmd 2 минуты назад

    Definitely, the folks looking at it as increasing from 1 to 2% are identifying the quickest accurate way to get it. I thought about it as an iterative search via an analogy of Newton's method with my intuition pointing towards something like 10 to 25 leaving the room. And, the mental math should be quick: 0% are left handers when 99 have left the room. So, the midpoint is about 50, let's look there, and that's the answer. But, that was just a happy coincidence. I was prepared for it to be too low again and needing to go to 25 leaving and finding that ratio might be too high or low and needing to either have more or less than 25 leave. .

  • @ATHIP12
    @ATHIP12 5 часов назад

    I immediately wondered if the question allowed us to round down. If that's the case, we need 34 people to leave to get it to 66/65 or 98.48%.

  • @YDS8479
    @YDS8479 8 часов назад +1

    i love all these maths puzzles

  • @Shadozcreeping
    @Shadozcreeping 2 часа назад

    50.
    99 out of 100 is 99%
    49 out of 50 is 98%, so half of the people in the room need to leave before the right handed individual could constitute 2% of the room's population

  • @RavenMobile
    @RavenMobile 7 часов назад +1

    Haven't watched the video yet, but I came up with 50 in about 5 seconds. I think my math is right. Take away 1 person and you have 1/99 right-handed. To get that to 98% it needs to be 1/50, so take away 50 lefties.

    • @qekruxt5089
      @qekruxt5089 7 часов назад

      solving a puzzle faster than someone else doesn't mean you have the higher IQ, fyi

  • @wiggles7976
    @wiggles7976 5 часов назад

    We have 1 right handed person, 99 left-handed. We need 98/100 people left handed, or 49/50 people left handed, so if 50 left-handed people leave, we have 49 left-handed, and 1 right-handed, achieving the required ratio.

  • @palpytine
    @palpytine 4 часа назад

    Flip it. There's 1% of right handed people, you need to DOUBLE that percentage, which means halving the number of people who aren't right-handed.

  • @averageboulderer
    @averageboulderer 5 часов назад

    50. 49:1 makes exactly 98% lefties. Anything over 49 lefties make it 98+some change.

  • @JDrapic
    @JDrapic 5 часов назад

    Pre-video solving, another way to think of it is "what is 1 2% of?". You need to reduce the total to 50, so 50 left-handers should leave.

  • @44daggers44
    @44daggers44 7 часов назад

    The right hander is 1% of the room. To double his percentage value, you have to halve the room.

  • @Antoni2602
    @Antoni2602 7 часов назад +2

    30 second time frame to answer and here is this guy explaining it from 1:24 to 8:30, way too long of a thought process :(

  • @yikaiye9241
    @yikaiye9241 5 часов назад

    if you want something to double its share without changing the number of that thing, cut the total by half.

  • @Dexaan
    @Dexaan 7 часов назад +1

    I've seen this one before, probably either here or Numberphile. The trick is indeed to flip the question to focus on the right-handed person (the left-handers are sinister anyway) - how many people need to be in the room to make them 2%? 50.

    • @HpPmL
      @HpPmL 46 минут назад

      Where does it say someone is right handed ? Did you just assume this person's laterality ?
      This person could identify as an ambidextrous or a non-armed person.

  • @Frank-kq4te
    @Frank-kq4te 6 часов назад

    Think the other way around , 1/100 is righthanded, so 1%. In order to duble the percentage, you need to half the quantity, because 1/50 is 2%. So if you remove 50 lefthanders, then 1 righthanded among 50 people will be a 2%. That leaves a 98% of lefthanded people in the room.

  • @donhartfield
    @donhartfield 3 часа назад

    It's not paradoxical. Its recursive because the total number in the room shrinks at the same rate as the number being measured are, leaving only a tiny fraction of change.

  • @fiathla
    @fiathla 7 часов назад +1

    It's just me, or these videos are becoming easier with the years?

  • @pklimbic
    @pklimbic 5 часов назад

    One person represents one percent of 100. Of what number (of persons ) does the one person represent 2%? If you ask it like this, you have it in 10 seconds.

  • @krzysztofmazurkiewicz5270
    @krzysztofmazurkiewicz5270 7 часов назад

    There was a simmilar question with something that weighted 100kg and 99% was water, And the question was how much water needs to go to have this thing contain 98% of water. So as long as one remembers the math its a quick one ;)
    Edit: yes it was the 100kg potato riddle ;)

  • @briant7265
    @briant7265 5 часов назад

    0 people need to leave, 1 left-handed and -1 right-handed.

  • @RavenMobile
    @RavenMobile 7 часов назад +1

    You're wildly overcomplicating your answer with the algebra. All you need to understand is the basics of percentages.
    1/100 = 99%
    1/? = 98%
    That is a doubling of the proportion of non-lefties in the room, so we need half as many total people in the room to accomplish that.

  • @mikoaj1349
    @mikoaj1349 4 часа назад

    I did solve this in under 30 seconds with no problem, but I had access to pen and paper. I don't know if they have those on the show and I doubt I'd be able to calculate this in memory, and under time pressure to boot.

  • @RobG1729
    @RobG1729 4 часа назад

    Think about the percentage of people NOT left-handed.
    That one person has twice the value, so half the number.
    Yes, that was what first occured to me.

  • @BKNeifert
    @BKNeifert 4 часа назад

    I figured it out, but only as you explained the problem. It's 50. 49/50. 98/100 reduces to 49/50

  • @nitailevi8001
    @nitailevi8001 6 часов назад

    Solved it, but took longer than 30 seconds. I didn't measure but probably close to a minute. Under pressure in a live show it can be a lot more difficult.

  • @Prs722
    @Prs722 7 часов назад

    My brain has always seen math differently. I never used a formula to go back and forth between a decimal and a percentage. I also always saw fractions as being the same as decimals. Converting between the three, I instantly see 1/50 as 2%. My brain sees that one can simplify 2/100 to 1/50 and that they are equal.

  • @daakudaddy5453
    @daakudaddy5453 6 часов назад

    I immediately knew that the answer is NOT 1. I think I took more than 30 seconds to arrive at 50. I am tired, sleepy, and in bed. I am also smart, but not too much. So definitely a lot more than 1% of people can solve this in 30 seconds.

  • @chrilaur1143
    @chrilaur1143 7 часов назад

    Yup…same as the watermelon puzzle. Knew the answer straight away.

  • @Songfugel
    @Songfugel Час назад

    Ugh, it's just 1/100 right handers to 2/100 which is 1/50, so 50 out of 99 left handers has to leave, and that is the answer

  • @richardfarrer5616
    @richardfarrer5616 3 часа назад

    The first time I saw this (about potatoes losing a percentage of water), it may have taken me 30 seconds+. But I wish I'd been on the show since it took less than a second this time.

  • @evanrosman9226
    @evanrosman9226 4 часа назад +1

    50.

  • @Kounomura
    @Kounomura 6 часов назад

    This problem can be better understood in connection with another, but mathematically identical problem. As Christmas approaches, we give gifts. If I gave gifts to 100 people last year, including myself, at Christmas, but this year I want to give twice as many gifts out of the same amount of money, by how much should I reduce the number of people I give gifts to?

  • @barneyDcaller
    @barneyDcaller 5 часов назад

    (99 - x)/(100 - x) = 0.98
    99 - x = 0.98 (100 - x)
    99 - x = 98 - 0.98x
    99 - 98 = x - 0.98x
    1 = x - 0.98x
    1 = 0.02 x
    x = 50

  • @Meshamu
    @Meshamu 4 часа назад

    To be frank, I feel this question would fit in better on "Are You Smarter Than A Fifth Grader?"

  • @raileite5994
    @raileite5994 6 часов назад

    God damn, 2 minutes to finally start solving a problem he already solved previously with a different "name"

  • @feedbackzaloop
    @feedbackzaloop 7 часов назад

    The real key to all these intellectual games for pseudointellectuals is that questions are typical and somewhat standard. So here one has to remember the problem about 99% dried fruit loosing weight from long ago.

  • @verkuilb
    @verkuilb 7 часов назад +3

    Another answer is that NOBODY needs to leave. You just saw the left arm off of one lefthanded person in the room. That person is now right-handed-meaning that 98 of 100 are lefties, or 98%.

    • @RavenMobile
      @RavenMobile 7 часов назад

      Just simplify it as "Remove around 1/8th of a leftie (their left arm) and 98% are now right-handed."
      Beautiful answer! I would award you full points, as it fits all given criteria.

  • @hikari1690
    @hikari1690 5 часов назад

    My gut is telling me 50 but my brain is too sleepy to do the maths for me

  • @porth5165
    @porth5165 2 часа назад

    1 out of x = 2%, x=50, therefor 50 have to leave

  • @jeremiahlyleseditor437
    @jeremiahlyleseditor437 7 часов назад

    I've seen this done in college some decades ago. I think the answer was 50 or so.

  • @KW-gb9cd
    @KW-gb9cd Час назад

    If 1 person is 2%, then 50 people would be 100%; the answer is 50.

  • @CharlesReiche
    @CharlesReiche 4 часа назад

    1 is 2% of what number. 50. Took me about 10 seconds to figure out.

  • @33LB
    @33LB 7 часов назад

    i got the answer to this, but admittedly it was because i am familiar with the potato paradox. i'm not so sure that i would have gotten this if i had to calculate it from scratch in 30 seconds, regardless of mensa membership.

  • @joeschmo622
    @joeschmo622 4 часа назад

    Yeah, this was just posted on another channel (thought it was a repeat here at first). Everyone's doing the iterative 99, 98, 97, etc., but I did it from the thumbnail question in like 10sec (if that) by thinking of the 1RH for 99% and 2RH for 98%, so 1/50 vs 1/100, meaning fitty people gots ta go.

  • @UncleJoeLITE
    @UncleJoeLITE 2 часа назад

    Yep, I just did 0.98 = 49/50. Thanks from Canberra 🇦🇺 Presh.

  • @RyanDouglas-h3d
    @RyanDouglas-h3d 19 минут назад

    2% of X = 1
    X = 1/.02 which is 50

  • @prithvisinghpanwar007
    @prithvisinghpanwar007 3 часа назад +1

    Stolen from BPRP

  • @brandorrrrgaming1544
    @brandorrrrgaming1544 7 часов назад

    I knew it was 50 in about 10 seconds but it was intuition

  • @NoFutureinLove
    @NoFutureinLove 7 часов назад

    So 100% of the comments solved the puzzle....and THIS is quite amazing...

  • @marvhollingworth663
    @marvhollingworth663 59 минут назад

    I didn't time how quick I got this but I'm pretty sure it took less than 30 secs. I just thought about the fraction of people that had to be right-handed. It started at 1/100 & had to double to 1/50, which meant 50 people had to leave.

  • @joaovitormatos8147
    @joaovitormatos8147 6 часов назад

    What if the right-handed guy left the room

  • @tannereustace
    @tannereustace 2 часа назад

    I wonder how many people say 49 in accidentally subtracting from 99 instead of 100 despite understanding the logic. Maybe that’s just me?

  • @TheLucanicLord
    @TheLucanicLord 2 часа назад

    I said 49. Spotted the logic trap, did the arithmetic wrong.

  • @GraveUypo
    @GraveUypo 6 часов назад

    50
    took me 1 second.

  • @yoav613
    @yoav613 7 часов назад

    98%=49/50 so 50 need to leave.

  • @isambo400
    @isambo400 7 часов назад

    Its easy with people but hard with pitato

  • @rayudurayudu9348
    @rayudurayudu9348 Час назад

    This is mathematically may be correct but logically making no sense because
    99% is equal to 100 people
    49.5% is equal to 50 people
    Anyone clarify here

  • @artemis5168
    @artemis5168 27 минут назад

    Ok, so here's my issue; if you're going to be rounding here, it makes it a completely different problem. 98.98989898...% is not logically 99%. It should be phrased to specify exactly 98%, or 98% within a certain margin of error. By the logic of the video, at 8:41, the same percentage of people in the room are right-handed when one person leaves as opposed to 4, or even 10. If you're going to round 98.9xxxxx up to 99%, then you're essentially stating the two are mathematically equivalent, which in this case is clearly ridiculous.
    I understand the math behind it, but the phrasing should be more specific to state "exactly 98%"", or something along those lines. 99% and 98.xxxxx% are not the same.

  • @molpegames
    @molpegames 7 часов назад

    My thought process: I need to find an amount of people where the one person is 2%. That is when there is only 50 people in the room, therefor 50 people need to leave. 🎉

  • @muralik98
    @muralik98 7 часов назад

    (99-x)/(100-x) = 0.98.
    solving for x. x=50

  • @marc_frank
    @marc_frank 6 часов назад

    f(x)=(99-x)/(100-x), intersect with 0.98
    yeah not very smart

  • @vcvartak7111
    @vcvartak7111 2 часа назад

    This problem is not similar to watermelon problem.

  • @aurochrok634
    @aurochrok634 15 минут назад

    50. where’s my 97k GBP? 😂

  • @grgfrg7
    @grgfrg7 40 минут назад

    Ok but what percentage of MindYourDecisions viewers can solve in 30 seconds?

  • @kinnoinen
    @kinnoinen 6 часов назад

    So did the contestant get it right?

  • @muhannawa
    @muhannawa 7 часов назад

    X/X+1. =.98

  • @MichaelCouvillion
    @MichaelCouvillion 7 часов назад

    Zero. Add right-handed people.

  • @Perokoulos
    @Perokoulos 7 часов назад

    Same question as the math guy with the two colour markers... Don't remember the name!

    • @_Dearex_
      @_Dearex_ 7 часов назад +1

      Black pen Red pen

  • @---Sasha---
    @---Sasha--- 3 часа назад

    1 second solve, nice vid tho

  • @BIueCat
    @BIueCat 7 часов назад

    I saw this and knew the answer because of this channel!

  • @giantswingallday7001
    @giantswingallday7001 5 часов назад

    50 people

  • @MrWarlls
    @MrWarlls 6 часов назад

    Less than 10s to find the answer.