I don't understand the people complaining in comment section. This is a great explanation. Instead of just showing the method you made us familiar with how to attack these kinds of problems. Great video !
i guessed 121 before i ever started writing anything down. as i tried to figure it out, i quickly became lost. i guess these videos are helping me figure out some logical loops you can go through to figure out some tricky questions.
@@idonotlikethismusic Yeah, I was studying for the GRE on here, and in some ways the actual exam was harder because of the time limit and whatnot. It can really be a pain in the butt, even with lots of preparation.
Thank you for saying so. And as helpful as these videos on my RUclips channel are, I know you'll find my comprehensive course content even more so. I'd love to go deeper with you and really help you boost your scores! You can learn more about my courses and choose the one that's right for you here: www.dominatethegre.com/gre-prep-courses-online/.
27. That's what I explain at ~4:30. There must be some overlap (i.e. "both") because 142 + 121 is more than the total number of students (236). So it has to be the case that some of the students are in both classes. At a minimum, there must be 142 + 121 - 236 = 27. There could be more, as I explain in the rest of the video, but at a minimum there must be at least 27.
I used chemistry to solve this problem 😂😂. In chemistry the LIMITING FACTOR determines how much of a particular product you can get. Because chemistry is the limiting factor 121 becomes the answer to the question
Just asking out of curiosity, if we were asked to find the minumum A’ that will be 21, right? Since, in the third scenario when we subtract the AnB from A, we get 21. Am I right? Furthermore, if asked to find A’nB or vice verse, how do I solve for it?
For those of us that have little math knowledge how do we know which formula to use? There are so many that takes it you to the same result. While your taking the test you only have like 2.5 or less to answer how can one go over that?
It's me Yes. Me It comes with coaching and practice. Think of it like tools in a tool box. How do you know you need a hammer instead of a screwdriver? Because the project involves nails, not screws. Same thing on the GRE. Fill your GRE toolbox with all of the different strategies and methodologies, and then practice until you’re good at using the right ones for the right questions. Our courses teach you exactly how to do that. Stick with it, you’ll get there!
what would be wrong in assuming a perfect overlap? 142 took algebra, 121 took chem, 142 +121 = 263. 263 -236 =27 which means 27 students are already taking both out of the 236 total. If we assume 0 students take neither of the two classes then we have 236 - 27 == 209 students who are taking either algebra or chem. Thus should the max no of students who COULD take both be equal to 209?
"Both" means students who took both algebra and chemistry, but doesn't include students who only took one or the other. So when you correctly added 142 + 121 = 263 and realized that the overlap is therefore 27, that number 27 represents the "both" that the question is asking about. So in fact that would be the MINIMUM number who could potentially have taken both classes, not the max. Instead, the "perfect overlap" you're talking about is if the chemistry circle were fully inside the algebra circle resulting in the largest possible overlap, i.e. the greatest possible number of students in the "both" category, which would be 121.
I understand why you went slowly step by step to show how the GRE can trick us but I think you should have reminded us how to quickly find the answer since the GRE is all about finding the correct answer in the most accurate and fast way.
Speed comes from pattern recognition, implementing the correct strategy, and of course practice. There's a time and place for solving questions quickly, but the purpose of this video was to teach the underlying concepts so that you can apply it (more quickly!) to similar questions in the future. And of course if you're interested in learning how to solve every GRE question type in the fastest and most effective way possible, consider our comprehensive GRE prep course: www.dominatethegre.com/gre-prep-courses-online/full-gre-course/. Hope to have the chance to work with you!
It doesn't seem as hard once everything makes sense. But is it necessary to do whole 3 diagrams everytime you're solving such problems, can't you just minus the smallest group of either because that obviously has the greatest possibility?
Siddharth Chowdary Vunnam For this particular question, yes. But in general it’s a good idea to sketch out the Venn Diagram so that you’re prepared to answer any question variation, including one that may not be as straightforward.
@@DominatetheGRE I was thinking 1 as the least number of students that can take both .. but when you derived the eqution 27 came up as least number so I am a little confused
Start watching again at the 4:25 mark. I answer it there. The "least" possible overlap will happen when "Neither" equals 0. In other words, if every single student is accounted for between algebra and chemistry, that will minimize the number of students taking Both. And remember we already worked the equation down to a scenario where we have Both - Neither = 27. So if Neither = 0, then Both = 27. That's the least possible number for Both.
@@shreypatel9379 dude what's your problem? Why try to ignite a quarrel? And don't use 'tf' and all. And if you can't solve this question in 2 mins, so be it. I just found it v easy to be on a youtube explaining video. Get the fuck out, man. Maybe if you studied a little instead of reading youtube comments, you'd have been faster.
If 121 took both Algebra and Chemistry, that means 21 took only Algebra and 0 took only Chemistry. So 121 + 21 + 0 = 142, which is the number of people that took one or the other or both. Since there were 236 students in the class, that would mean that 236 - 142 = 94 students took NEITHER chemistry nor algebra. The total of 236 is still there, it's just not all that relevant for this particular question.
There is no information about other students. If they wrote 'All of 236 students take algebra, or chemistry, or both', you would be right. However, we are not provided by this information - may be the rest of them who do not take algebra, or chemistry, or both take physics? You should not speculate about such information.
I think you have it backwards. Unless otherwise indicated, it's possible that some of the total population falls into the "neither" category. That's the assumption on all "sets" questions like this. As you said, sometimes the question will specify that all participants do one or the other or both, and that tells you that "neither" = 0. But that's not the case in this particular problem.
I'm not sure I fully understand your question. The formulas you'll use on the GRE have already been "designed" by famous mathematician such as Pythagoras and Archimedes. You just have to choose/use the right formula when appropriate. There isn't really a relevant formula for this particular problem, however, which is why I approach it the way I do in this video. But if you're interested in how to use the formulas that are tested on the GRE, it sounds like you'll benefit from my comprehensive GRE math course: www.dominatethegre.com/gre-prep-courses-online/full-quantitative-course/.
Kritika Garg the question already states that only 142 students took algebra and 121 took chemistry. The (could have taken) part doesn’t mean could’ve taken both before choosing the subjects. It’s asking about the greatest number after the students chose and took those classes. Since only 121 took chemistry, it’s the greatest number for both subjects. It can’t be 142 coz not more than 121 took chemistry class.
There is no information about other students. If they wrote 'All of 236 students take algebra, or chemistry, or both', you would be right. However, we are not provided by this information - may be the rest of them who do not take algebra, or chemistry, or both take physics? You should not speculate about such information.
He tried to show how to attack these kind of problems, what kind of thinking goes into solving them. There's many such problems I've solved where the answer was derived from that 'irrelevant' equation he formed.
The "least" number would happen when Neither = 0, in which case Both = 27. You can re-watch my Scenario 1 explanation starting at 4:00 to see how that works.
I don't understand the people complaining in comment section. This is a great explanation. Instead of just showing the method you made us familiar with how to attack these kinds of problems. Great video !
Thank you, Shrey. I'm glad you resonated with what I was trying to do with this video and found it helpful!
It was an easy solution but the way you explained differentiating max/min is blessed. Keep up the good work 👍
Thank you!
Classic example of how to take simple questions and make them sooo complicated
hahaha
he's explaining how to think about everything. maybe you should listen. you will score higher on the gre.
🤣
i guessed 121 before i ever started writing anything down. as i tried to figure it out, i quickly became lost. i guess these videos are helping me figure out some logical loops you can go through to figure out some tricky questions.
Awesome, glad it helped frame your thinking!
Me too. I figured it out intuitively once you drew the first scenario's Venn diagram. Thanks
Thanks a lot for the excellent question !
My pleasure, glad it helped!
is there any formula that we can use to find min max for 3 set questions?
Thank you very much, very nice and helpful explanation!
My pleasure, glad it helped!
It sounds like they try to trick you by giving a bunch of nonessential information.
Usually every word in a GRE word problem has a purpose. What do you find to be nonessential information in this question?
@Sudhir Kakar As long as the number who took algebra is more than 121, yes.
The problem is that time pressure on GRE, combined with wordiness, makes otherwise simple questions difficult
@@idonotlikethismusic Yeah, I was studying for the GRE on here, and in some ways the actual exam was harder because of the time limit and whatnot. It can really be a pain in the butt, even with lots of preparation.
Your are the best teacher.. I am watching your video fully.
Thank you for saying so. And as helpful as these videos on my RUclips channel are, I know you'll find my comprehensive course content even more so. I'd love to go deeper with you and really help you boost your scores! You can learn more about my courses and choose the one that's right for you here: www.dominatethegre.com/gre-prep-courses-online/.
So if the question said minimum instead of maximum. Will it be 0 or 27 and why?
27. That's what I explain at ~4:30. There must be some overlap (i.e. "both") because 142 + 121 is more than the total number of students (236). So it has to be the case that some of the students are in both classes. At a minimum, there must be 142 + 121 - 236 = 27. There could be more, as I explain in the rest of the video, but at a minimum there must be at least 27.
it's seems that sound explanation, thank you
Great, glad you found it helpful!
great trick
Thank you. Glad you found it helpful!
I got 161 in Quant, but the sets question was even harder than this, it included 3 groups of students.
I mean, if you see such questions, be sure you're doing well and about to get high score ^_^
I teach "3 Groups" Sets questions in my Full GRE Quantitative Course: www.dominatethegre.com/gre-prep-courses-online/full-quantitative-course/
I used chemistry to solve this problem 😂😂. In chemistry the LIMITING FACTOR determines how much of a particular product you can get. Because chemistry is the limiting factor 121 becomes the answer to the question
Spot-on!
In less than 10 seconds,, I guess that 121....
cool story bro
Just asking out of curiosity, if we were asked to find the minumum A’ that will be 21, right? Since, in the third scenario when we subtract the AnB from A, we get 21. Am I right? Furthermore, if asked to find A’nB or vice verse, how do I solve for it?
For those of us that have little math knowledge how do we know which formula to use? There are so many that takes it you to the same result. While your taking the test you only have like 2.5 or less to answer how can one go over that?
It's me Yes. Me It comes with coaching and practice. Think of it like tools in a tool box. How do you know you need a hammer instead of a screwdriver? Because the project involves nails, not screws. Same thing on the GRE. Fill your GRE toolbox with all of the different strategies and methodologies, and then practice until you’re good at using the right ones for the right questions. Our courses teach you exactly how to do that. Stick with it, you’ll get there!
what would be wrong in assuming a perfect overlap? 142 took algebra, 121 took chem, 142 +121 = 263. 263 -236 =27 which means 27 students are already taking both out of the 236 total. If we assume 0 students take neither of the two classes then we have 236 - 27 == 209 students who are taking either algebra or chem. Thus should the max no of students who COULD take both be equal to 209?
"Both" means students who took both algebra and chemistry, but doesn't include students who only took one or the other. So when you correctly added 142 + 121 = 263 and realized that the overlap is therefore 27, that number 27 represents the "both" that the question is asking about. So in fact that would be the MINIMUM number who could potentially have taken both classes, not the max. Instead, the "perfect overlap" you're talking about is if the chemistry circle were fully inside the algebra circle resulting in the largest possible overlap, i.e. the greatest possible number of students in the "both" category, which would be 121.
I understand why you went slowly step by step to show how the GRE can trick us but I think you should have reminded us how to quickly find the answer since the GRE is all about finding the correct answer in the most accurate and fast way.
Speed comes from pattern recognition, implementing the correct strategy, and of course practice. There's a time and place for solving questions quickly, but the purpose of this video was to teach the underlying concepts so that you can apply it (more quickly!) to similar questions in the future. And of course if you're interested in learning how to solve every GRE question type in the fastest and most effective way possible, consider our comprehensive GRE prep course: www.dominatethegre.com/gre-prep-courses-online/full-gre-course/. Hope to have the chance to work with you!
So the minimum for this problem would be, 27 right? It helped me btw. I had difficulties with topic. Well guess what, not anymore
Yep, that's right. Glad this video helped you!
*Great! Keep up the good work! Loved the video.
Awesome, thanks Mahmud!
Will this solution work for most problems exactly like this asking for the overlapping greatest number?
It doesn't seem as hard once everything makes sense. But is it necessary to do whole 3 diagrams everytime you're solving such problems, can't you just minus the smallest group of either because that obviously has the greatest possibility?
Siddharth Chowdary Vunnam For this particular question, yes. But in general it’s a good idea to sketch out the Venn Diagram so that you’re prepared to answer any question variation, including one that may not be as straightforward.
Dominate the GRE
Thanks, means a lot to hear back from you!
What if we had to find the least number?
Using the same logic, you tell me. What do you think?
@@DominatetheGRE I was thinking 1 as the least number of students that can take both .. but when you derived the eqution 27 came up as least number so I am a little confused
Start watching again at the 4:25 mark. I answer it there. The "least" possible overlap will happen when "Neither" equals 0. In other words, if every single student is accounted for between algebra and chemistry, that will minimize the number of students taking Both. And remember we already worked the equation down to a scenario where we have Both - Neither = 27. So if Neither = 0, then Both = 27. That's the least possible number for Both.
Thanks
Um, I 'solved' this in 2 seconds, literally.
30, but agree, not challenging
Good for you, need an accolade for the same?
Akshat Khurana, keep your sarcasm to yourself. No one asked you to come to my thread. Trying to be sassy.
@@aryamantewari5122 Tf you flexing about my guy ? Mr 'I solved in 2 seconds'
@@shreypatel9379 dude what's your problem? Why try to ignite a quarrel? And don't use 'tf' and all. And if you can't solve this question in 2 mins, so be it. I just found it v easy to be on a youtube explaining video.
Get the fuck out, man. Maybe if you studied a little instead of reading youtube comments, you'd have been faster.
Where did 236 go. I mean it wont end up to 236 is summed
If 121 took both Algebra and Chemistry, that means 21 took only Algebra and 0 took only Chemistry. So 121 + 21 + 0 = 142, which is the number of people that took one or the other or both. Since there were 236 students in the class, that would mean that 236 - 142 = 94 students took NEITHER chemistry nor algebra. The total of 236 is still there, it's just not all that relevant for this particular question.
There is no information about other students. If they wrote 'All of 236 students take algebra, or chemistry, or both', you would be right. However, we are not provided by this information - may be the rest of them who do not take algebra, or chemistry, or both take physics? You should not speculate about such information.
I think you have it backwards. Unless otherwise indicated, it's possible that some of the total population falls into the "neither" category. That's the assumption on all "sets" questions like this. As you said, sometimes the question will specify that all participants do one or the other or both, and that tells you that "neither" = 0. But that's not the case in this particular problem.
Thankyou ^_^ got it ^_^
Thank you. Had the same doubt here.
How do you design formulas.. i m more interested jn that
I'm not sure I fully understand your question. The formulas you'll use on the GRE have already been "designed" by famous mathematician such as Pythagoras and Archimedes. You just have to choose/use the right formula when appropriate. There isn't really a relevant formula for this particular problem, however, which is why I approach it the way I do in this video. But if you're interested in how to use the formulas that are tested on the GRE, it sounds like you'll benefit from my comprehensive GRE math course: www.dominatethegre.com/gre-prep-courses-online/full-quantitative-course/.
What just happened? It took me only the time to read the whole question to solve this. LOL
Nice work!
But why can't it be 236 ...that all the students could have taken both algebra and chemistry?
BTW Thanks for the videos. They are really helpful
Kritika Garg the question already states that only 142 students took algebra and 121 took chemistry. The (could have taken) part doesn’t mean could’ve taken both before choosing the subjects. It’s asking about the greatest number after the students chose and took those classes.
Since only 121 took chemistry, it’s the greatest number for both subjects. It can’t be 142 coz not more than 121 took chemistry class.
There is no information about other students. If they wrote 'All of 236 students take algebra, or chemistry, or both', you would be right. However, we are not provided by this information - may be the rest of them who do not take algebra, or chemistry, or both take physics? You should not speculate about such information.
The question has no honor. :((((
your methods are sagacious but it has a too lengthy solution
Actually, this is the easiest version of this kind of problem.
Glad you found it easy. Hopefully that bodes well for you on test day!
I do not understand
My "Common GRE Word Problems" lessons will help (especially the one on Sets problems): www.dominatetestprep.com/store/rQ2gjTrV
Answer in 0.5 mini second ...wtf bro
Nice work!
Wow bro, where is your trophy?
What in the hell was this explanation? The formulas you came up with equaling 27 aren't even relevant...all that to get 121 lol. Terrible
He tried to show how to attack these kind of problems, what kind of thinking goes into solving them. There's many such problems I've solved where the answer was derived from that 'irrelevant' equation he formed.
What if we had to find the least number?
The "least" number would happen when Neither = 0, in which case Both = 27. You can re-watch my Scenario 1 explanation starting at 4:00 to see how that works.