Great videos sir, Can you please make a video which gives an overview of all the different strategies that are required to deal with different patterns of quant questions in the GRE.
for consequent percentage changes like 20% up and 20% down and etc. theres a formula to get the net % change -> (A) + (B) + ( (A*B)/100 ) so for 20% increase and 20% decrease we can simply do -> 20 + (-20) + ( (20 * -20) / 100 ) -> 20 - 20 - 4 -> -4 % change Hope this helps , i applied it in the next question too and got answer very quickly
Hi, thanks so much for the explanations! I'm a bit confused for Q8 though. Since this is a frequency table, do we not add up the total number of secondary teachers in the whole column, then get the median'th number of teacher (in frequency) and then go down each row adding the frequencies cumulatively to see which region that median'th no. of teacher lies? That way i got Eastern Asia but since that wasn't an option, my approach was to go with the next closest region which was (D) South-eastern Asia but i'm not sure about this way.
The reason the method you suggest doesn't work is the table presenting the data for this question isn't a frequency table. The method you suggest would be perfect if the table categorized teachers according to their height and we were trying to find the median height teacher. We could line all the teachers up from shortest to tallest and select the teacher in the middle of the line. In this case, that method doesn't make sense because we can't line the teachers up. Who would go at the 'bottom' of the line? The teachers from Northern Africa, Europe, or somewhere else? Instead, we have a series of numbers of teachers according to where those teachers live. We know Northern Africa has 993 secondary teachers, Sub-Saharan Africa has 1,172, and so on. If we put these numbers in order from least to greatest, we can find the median number of teachers by selecting the number in the middle of that list. I hope that helps!
In Question 9, I feel the answer should be (B) 2/3 because they have asked how many times greater? It is 863 thousand greater which is (2/3)rds. of 1340.
This all comes down to the wording of the question. You're absolutely right that 863 is approximately 2/3 of 1340, but that's not what we're asked to find in this question. We have to put find the number we would multiply 1340 by to get 2203. It turns out that 1340 * (5/3) = 2233, so the number of secondary teachers in South-eastern Asia is approximately 1 2/3 times greater than the number of secondary teachers in Western Asia. This is why the answer to this question is (D). I hope that helps!
I think the answer to the last question is SUB SAHARAN AFRICA even though it is not among the options because going by your explanation the ratio is approx 0.1 for that region. Or was there a reason for the ommission?
This is one of those situations in which you need to be very careful with the wording of the question. We're asked "For which of the following regions is the ratio...smallest." This means we're limited to looking at the regions mentioned in the answer choices and only those regions. We can (and should) ignore any other region mentioned in the table. There's no reason why Sub-Saharan Africa was left out. However, the fact that it is not one of the options means it cannot be the answer to this question, even though you're absolutely right that Sub-Saharan Africa has the lowest value for the ratio of all the regions in the table. I hope that helps!
Between the solid black lines representing 10% and 20%, there are four lighter lines. This means each line represents 2%, so we can split the 10-20% interval into 10, 12, 14, 16, 18, and 20. For the second six month period, City A sees an increase in subway passengers that is halfway between the first and second light lines above the 10% mark. The first light line represents a 12% increase and the second light line represents a 14% increase. Since we're looking halfway between 12 and 14%, we can say the number of subway riders increased by 13%. I hope that helps!
38:08 How do you know the answer 9600 is the difference between "the average number"? Aren't they just riders of the day? How should I account the word "average" in this problem?
You're right that this is a problem with the wording of this question. We should have said that "City C and City D both had an average of 120,000 passengers per day at the end of 2020" at the start of this question. The good news is that the question writers at the GRE have much more time and resources to test and refine their questions than we did when we wrote this series. You shouldn't come up against a problem like this when you take the GRE for real. Thank you for your comment, and I hope that helps!
You get to use an on-screen calculator on the GRE quant section. Check out the link below for more details on what the calculator can do. I hope that helps! www.ets.org/pdfs/gre/on-screen-calculator-guidelines.pdf
The information in the table tells us there are 26,159 students in tertiary education and 40,601 students in primary education in Europe. This means the ratio of students in tertiary education to students in primary education in Europe is 0.644. This is much greater than the ratio of 0.27 Harry found for Northern Africa. Since this question asks us to find the region for which the ratio is smallest, Europe is not the answer to this question. Instead, the answer is Northern Africa or (A). I hope that helps!
question 4 wasn't the most efficient. we didnt need to calculate the percentage change. I know if i double 233M i get 466 thats a 100% change. If i add another 233M i get 699M. thats 200%. My answer is 220%. im enjoying this. thanks
You're correct that there are quicker ways of answering this question. I wanted to include the percentage change formula as it comes up a lot in GRE Data Interpretation questions. While the numbers in this question worked out and we could have used the formula you suggested to quickly reach the correct answer, the numbers won't alweys be so nice in other questions. If you're comfortable using the formula and using the estimation method you laid out, you're in a great position to take on these problems! Thank you for posting!
One of the best instructive videos I've seen so far for the GRE examination techniques.
Thank you so much for the kind words, and have fun studying!
Omitting the 6 zero values from both sides make the calculations a lot easier
Great videos sir, Can you please make a video which gives an overview of all the different strategies that are required to deal with different patterns of quant questions in the GRE.
for consequent percentage changes like 20% up and 20% down and etc. theres a formula to get the net % change -> (A) + (B) + ( (A*B)/100 )
so for 20% increase and 20% decrease
we can simply do -> 20 + (-20) + ( (20 * -20) / 100 )
-> 20 - 20 - 4
-> -4 % change
Hope this helps , i applied it in the next question too and got answer very quickly
Love from Pakistan ✨💕 GRE is all about tricks ✨ Thank you for sharing
You guys have helped me a ton in preparing myself for the second GRE attempt I will be taking today!
I might be too late to be useful, but good luck on the exam! I hope that you kicked all sorts of butt. And thank you for the kind words!
Does the calculator on the GRE allow you to input into the billions?
Hi, thanks so much for the explanations! I'm a bit confused for Q8 though. Since this is a frequency table, do we not add up the total number of secondary teachers in the whole column, then get the median'th number of teacher (in frequency) and then go down each row adding the frequencies cumulatively to see which region that median'th no. of teacher lies? That way i got Eastern Asia but since that wasn't an option, my approach was to go with the next closest region which was (D) South-eastern Asia but i'm not sure about this way.
The reason the method you suggest doesn't work is the table presenting the data for this question isn't a frequency table. The method you suggest would be perfect if the table categorized teachers according to their height and we were trying to find the median height teacher. We could line all the teachers up from shortest to tallest and select the teacher in the middle of the line. In this case, that method doesn't make sense because we can't line the teachers up. Who would go at the 'bottom' of the line? The teachers from Northern Africa, Europe, or somewhere else?
Instead, we have a series of numbers of teachers according to where those teachers live. We know Northern Africa has 993 secondary teachers, Sub-Saharan Africa has 1,172, and so on. If we put these numbers in order from least to greatest, we can find the median number of teachers by selecting the number in the middle of that list.
I hope that helps!
In Question 9, I feel the answer should be (B) 2/3 because they have asked how many times greater? It is 863 thousand greater which is (2/3)rds. of 1340.
This all comes down to the wording of the question. You're absolutely right that 863 is approximately 2/3 of 1340, but that's not what we're asked to find in this question.
We have to put find the number we would multiply 1340 by to get 2203. It turns out that 1340 * (5/3) = 2233, so the number of secondary teachers in South-eastern Asia is approximately 1 2/3 times greater than the number of secondary teachers in Western Asia. This is why the answer to this question is (D).
I hope that helps!
In mean problems, allways
think the mean in relation with what
PERCENTAGE CHANGE: (p2-p1)/p
x down 20% percent in periode1 and up 20 percent in period2 (that come afeter p1) so x*(0.8)*(1.2)
I think the answer to the last question is SUB SAHARAN AFRICA even though it is not among the options because going by your explanation the ratio is approx 0.1 for that region. Or was there a reason for the ommission?
This is one of those situations in which you need to be very careful with the wording of the question. We're asked "For which of the following regions is the ratio...smallest." This means we're limited to looking at the regions mentioned in the answer choices and only those regions. We can (and should) ignore any other region mentioned in the table.
There's no reason why Sub-Saharan Africa was left out. However, the fact that it is not one of the options means it cannot be the answer to this question, even though you're absolutely right that Sub-Saharan Africa has the lowest value for the ratio of all the regions in the table.
I hope that helps!
For Q7 How we know exactly city A up %13 ? I thought it is %15 from the graph
Between the solid black lines representing 10% and 20%, there are four lighter lines. This means each line represents 2%, so we can split the 10-20% interval into 10, 12, 14, 16, 18, and 20. For the second six month period, City A sees an increase in subway passengers that is halfway between the first and second light lines above the 10% mark. The first light line represents a 12% increase and the second light line represents a 14% increase. Since we're looking halfway between 12 and 14%, we can say the number of subway riders increased by 13%.
I hope that helps!
38:08 How do you know the answer 9600 is the difference between "the average number"? Aren't they just riders of the day?
How should I account the word "average" in this problem?
You're right that this is a problem with the wording of this question. We should have said that "City C and City D both had an average of 120,000 passengers per day at the end of 2020" at the start of this question.
The good news is that the question writers at the GRE have much more time and resources to test and refine their questions than we did when we wrote this series. You shouldn't come up against a problem like this when you take the GRE for real.
Thank you for your comment, and I hope that helps!
Thank you so much for your kind and professional answer it helped a lot. @@GRENinjaTutoring
is calculator allowed in the exams? i find these precise calculation difficult and i loose much time
You get to use an on-screen calculator on the GRE quant section. Check out the link below for more details on what the calculator can do.
I hope that helps!
www.ets.org/pdfs/gre/on-screen-calculator-guidelines.pdf
emm, is it just me or is solution to Q4 wrong?
shouldn't 220 % change = 120 % gain? Any thoughts? Anyone?
last ratio should be europe nw ?
The information in the table tells us there are 26,159 students in tertiary education and 40,601 students in primary education in Europe. This means the ratio of students in tertiary education to students in primary education in Europe is 0.644. This is much greater than the ratio of 0.27 Harry found for Northern Africa.
Since this question asks us to find the region for which the ratio is smallest, Europe is not the answer to this question. Instead, the answer is Northern Africa or (A).
I hope that helps!
question 4 wasn't the most efficient. we didnt need to calculate the percentage change. I know if i double 233M i get 466 thats a 100% change. If i add another 233M i get 699M. thats 200%. My answer is 220%. im enjoying this. thanks
You're correct that there are quicker ways of answering this question. I wanted to include the percentage change formula as it comes up a lot in GRE Data Interpretation questions. While the numbers in this question worked out and we could have used the formula you suggested to quickly reach the correct answer, the numbers won't alweys be so nice in other questions. If you're comfortable using the formula and using the estimation method you laid out, you're in a great position to take on these problems!
Thank you for posting!
The only section on GRE I'm sure I will pass haha