This video explains the concept of inequalities which is tested in exams such as GMAT, GRE and CAT. Share this video and show your appreciation @ Facebook.com/perfectscores.
@45:57 You flipped the inequality sign. Once you took |n| to the other side, the equation should've been 1> n|n|. Either way, that means n can only be more than -1, less than 1 and not 0. Statement one gives n=5,6,7... & -5,-6,-7... Therefore, none of the values from this statement give n so that |n| < 4. Statement two give a range of -1 < n < 1 and n not equal to 0. Which perfectly fits the |n| < 4 requirement.
On the question in the 41st minute, why is statement one and two considered sufficient when we can't get the exact values on x and Y with these statements?
In the last problem conclusion is wrong: statement B alone is not sufficient, because if both x and y are positive, e.g. x=4 and y = 9 than we get |4-9|
Sir, in the question at 32:00. the second statement is |3-y|=11. And from the first statement, it is certain that y>0. But, when we open up the modulus and say 3-y = -11, isn't y negative?And when you say 3-y = 11, isn't y positive?Therefore, aren't the answers contradictory?Because y
Good Job! Just a question....min 29.45 -> -0.5 -(-1)= 0.5, so both x and y can actually be negative right? I don't get why answer is C (both must be positive)
Hi Pushpinder! Firstly, Thanks a lot for the brilliant explanations in all of your videos, they are helpful compared to other video resources. Secondly, I'm a bit confused when it comes to "Finding the VALUE OF x+y" the question/explanation stated in 40th min. Does't that mean that the question asks for an EXACT VALUE ? Because if we try plugging in numbers and we get several answers i.e. considering option C, taking both the statements, we get x=3 & y=-7, x=4 & y=-8 etc. which (IMO) should NOT BE SUFFICIENT. Please throw some light !
To go to option C, you need to first eliminate A and D. That's the rule in Data Sufficiency Question. And in the explanation you will find that both statements are individually sufficient, hence the ans is D.
For -n = |n| can we not say that since RHS is +ve (magnitude of any value ) LHS should also be positive. Since LHS already has a - (minus) sign we need n to be less than zero(i.e.) so as to make LHS positive. So first statement suffices to draw the conclusion. Am I going wrong somewhere?
on the example you gave at the 30 min mark, shouldn't the answer be E? Combing statement 2 and statement 1, I find that X&Y can be both positive and both negative. For example, X can be -1/10 and Y can be -6/10 (satisfying both statement 1 &2) and X can be 3 and Y can be 2.5 (satisfying both statement 1 &2). Thus E, because X and Y can be both Positive or both negative.
+PerfectScores Sir, is the strategy of considering if x is positive |x+2| is (x+2) and when x is -ve |x+2| is -(x+2) right? Please clarify which of the following is right |x+2| = x+2 if x>0 or |x+2| = x+2 if x+2 > 0 => x > -2 I am totally confused......how the question(@ 40:30 ) is approached when analyzing the stem, the moment when we consider x and y values to make the table of outcomes. Thank you in advance.
Could you please explain the change of sign? If x + 2 = 4 (x is 2), then - (y + 2) = 4 (y is -6) hence 2 +(-6) should be -4 not 4. Is there a change of sign when doing x + y ? Thank you
hello sir,at last question of the video EVEN FOR BOTh negative x and y statement 2nd fails because if |X| |Y|...so it fails to be sufficient ..i think both equation will suffice ,so answer should be c..please clarify
From 17:20 you derive some information from the question stem algebraically. I do not fully understand the steps you take, especially the last step. Please could you recommend one of your (or other people's) videos that would show me how to manipulate algebra in the way you did there? Thank you.
PerfectScores Thank you for your reply. I will take some time to try to understand it. So it seems I need to be more proficient in quadratic equations? I will look for more videos on that. If you can point me to videos that will help me to strengthen my algebra, I would greatly appreciate it.
Pushpinder, There are two points I want to mention: First, 1/abs(n)>n becomes 1>abs(n)*n as abs(n) is positive. Second, in the second condition of the last question abs(x-y)abs(-2) or 3>2, which is the other way around. However, neither of these two points affect the answers. By the way, thanks for your great videos.
No, you have taken y=5, not y=-5. The point is that both are considered negative. I write again: x=-2, y=-5, then abs(-2-(-5))>abs(-2), then abs(3)>abs(-2) 3>2. This makes the inequality sign flip. On the other hand, x=-5, y=-2, then abs(-5-(-2))
SIR AT 38.29 question I think the question must me CAN WE FIND THE VALUE OF X+Y? then the answer is D But....the question given is to find the value of X+Y this means exact value we cannot find ???? please SOLVE MY QUERY??????????????????????????????????????????????????????????????????
at first i thought the same, but based on statement no 1 no matter what numbers you plug in for x and y as long as they satisfy |x+2| = |y+2| the answer will always be -4 for example if x=1 then y=-5, if x=7 then y=-11, if x=-8 then y=4.. x+y will always be -4. The numbers cant be x=y since xy < 1 (statement no 1) hope this helps bro
I dont think the answer of the question at 40:30 is correct, it should be E. The question is asking what is the definite value of x+y which is not obtained
i think it should be (B) because for any values given by statement 2,the value of x+y is always a 4 but statement 1 is not sufficient because the value of x+y cant be determined with the statement 1 n if u put the values of x and y (-x n +y once n then +x and -y),u will get different values of x+y satisfying |x+2|=|y+2|
Please I'm not really clear with the answer of |x+2|=|Y+2| . Please will the answer not be A given that in statement two, y could range from 1 to -infinity? If y
Hi Pushpinder, The answer to the question ending at 42:00 is E, not D. x+y is either 4 or -4 and the two conditions each can result in both 4 and -4 by assuming different values for x and y. Therefore, we cannot reach a certain answer (eirher 4 or -4) for this question and therefore the answer is D. Take a look at it please.
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@45:57 You flipped the inequality sign. Once you took |n| to the other side, the equation should've been 1> n|n|. Either way, that means n can only be more than -1, less than 1 and not 0.
Statement one gives n=5,6,7... & -5,-6,-7...
Therefore, none of the values from this statement give n so that |n| < 4.
Statement two give a range of -1 < n < 1 and n not equal to 0.
Which perfectly fits the |n| < 4 requirement.
You deserve many many thanks and love,you made my concept so much clear . Wish You become successful in your life..
On the question in the 41st minute, why is statement one and two considered sufficient when we can't get the exact values on x and Y with these statements?
And at 42:00 modulus of any number can't be negative! So how are we analyzing it here? And plus the question said that n
In the last problem conclusion is wrong: statement B alone is not sufficient, because if both x and y are positive, e.g. x=4 and y = 9 than we get |4-9|
No, even I had the same confusion.
sir , in second question the statement 2 cannot be satisfied because if Y
pushpinder........ genius,,,,,, loved it bro......
Sir, in the question at 32:00. the second statement is |3-y|=11. And from the first statement, it is certain that y>0.
But, when we open up the modulus and say 3-y = -11, isn't y negative?And when you say 3-y = 11, isn't y positive?Therefore, aren't the answers contradictory?Because y
Good Job! Just a question....min 29.45 -> -0.5 -(-1)= 0.5, so both x and y can actually be negative right? I don't get why answer is C (both must be positive)
Life savior! Brilliant explanation.
Hi Pushpinder!
Firstly, Thanks a lot for the brilliant explanations in all of your videos, they are helpful compared to other video resources.
Secondly, I'm a bit confused when it comes to "Finding the VALUE OF x+y" the question/explanation stated in 40th min. Does't that mean that the question asks for an EXACT VALUE ? Because if we try plugging in numbers and we get several answers i.e. considering option C, taking both the statements, we get x=3 & y=-7, x=4 & y=-8 etc. which (IMO) should NOT BE SUFFICIENT. Please throw some light !
To go to option C, you need to first eliminate A and D. That's the rule in Data Sufficiency Question. And in the explanation you will find that both statements are individually sufficient, hence the ans is D.
Best video on the subject. Thank you, sir.
For -n = |n| can we not say that since RHS is +ve (magnitude of any value ) LHS should also be positive. Since LHS already has a - (minus) sign we need n to be less than zero(i.e.) so as to make LHS positive. So first statement suffices to draw the conclusion. Am I going wrong somewhere?
awesome buddy , aweeeeeesome , just awesome. so awesome man
Pushpinder - at 38.00 why did you say that if y is -ve then |y+2| = -y-2 . isn't is will be -y+2 ?
Sir ur video are best sir really so exited to see more video sir but where is the plugging in number part 2 I hope u provide soon sir
Hi at 40:00 we are getting two different sets of possible answers! Is that right in value ds question?
while solving the inequality 1/|n|>n,why do you flip the sign?shouldn"t it be n|n|
same doubt
I think its a mistake. However, the answer still remains the same.
The problem at 42 minutes, why did you add 0? IF zero is neither positive nor negative, can we write -(-0)= |-0|?
for question y=lxl+x .... y
A brilliant video! You explain very well indeed. Thank you.
Hey,
At 52:30, what if we take the magnitude of y greater than x, when both being negative. I don't think statement two is correct over there.
Thanks
on the example you gave at the 30 min mark, shouldn't the answer be E? Combing statement 2 and statement 1, I find that X&Y can be both positive and both negative. For example, X can be -1/10 and Y can be -6/10 (satisfying both statement 1 &2) and X can be 3 and Y can be 2.5 (satisfying both statement 1 &2). Thus E, because X and Y can be both Positive or both negative.
disregard. I see that the numbers I provided won't work since X/Y>1
@40:30 when |x+2|=|y+2| and we know that xy
Rahul Kalra
If |a| = |b| then either a = b or a = -b. So in that sense either x + 2 = y + 2 or x + 2 = -(y + 2).
+PerfectScores Sir, is the strategy of considering if x is positive |x+2| is (x+2) and when x is -ve |x+2| is -(x+2) right?
Please clarify which of the following is right
|x+2| = x+2 if x>0
or
|x+2| = x+2 if x+2 > 0 => x > -2
I am totally confused......how the question(@ 40:30 ) is approached when analyzing the stem, the moment when we consider x and y values to make the table of outcomes.
Thank you in advance.
Could you please explain the change of sign? If x + 2 = 4 (x is 2), then - (y + 2) = 4 (y is -6) hence 2 +(-6) should be -4 not 4. Is there a change of sign when doing x + y ? Thank you
hello sir,at last question of the video EVEN FOR BOTh negative x and y statement 2nd fails because if |X| |Y|...so it fails to be sufficient ..i think both equation will suffice ,so answer should be c..please clarify
From 17:20 you derive some information from the question stem algebraically. I do not fully understand the steps you take, especially the last step. Please could you recommend one of your (or other people's) videos that would show me how to manipulate algebra in the way you did there? Thank you.
James Westwood
First we took y common and then solved the quadratic equation. x(x) + 9 - 6x = x(x) - 3x - 3x + 9 = x(X- 3)-3(x-3) = (x-3)(x-3)
PerfectScores Thank you for your reply. I will take some time to try to understand it. So it seems I need to be more proficient in quadratic equations? I will look for more videos on that.
If you can point me to videos that will help me to strengthen my algebra, I would greatly appreciate it.
Pushpinder,
There are two points I want to mention:
First, 1/abs(n)>n becomes 1>abs(n)*n as abs(n) is positive.
Second, in the second condition of the last question abs(x-y)abs(-2) or 3>2, which is the other way around. However, neither of these two points affect the answers.
By the way, thanks for your great videos.
abs(x-y)abs(-2)
The sign should be other way in the second one.
Exactly. That's what I said. So?
In different assumptions of x and y, both negative, two scenarios exist. One is abs(x-y)
I mean to say that your reasoning is incorrect. It should be abs(-2-5) < abs(-2)
No, you have taken y=5, not y=-5. The point is that both are considered negative.
I write again:
x=-2, y=-5, then
abs(-2-(-5))>abs(-2), then
abs(3)>abs(-2)
3>2. This makes the inequality sign flip.
On the other hand,
x=-5, y=-2, then
abs(-5-(-2))
grt video sir ,u r helping us a lot......can`t thank u enough.
Mr. gill is the type of question practiced here comes in GRE..i see its only for GMAT
PushpinderJi! When can we expect more lectures on permutations and combinations?
does the video cover CAT level questions too?????
sir iwant codded inequlities in banking sector .will u provide some more vedious
SIR AT 38.29 question I think the question must me CAN WE FIND THE VALUE OF X+Y? then the answer is D
But....the question given is to find the value of X+Y this means exact value we cannot find ????
please SOLVE MY QUERY??????????????????????????????????????????????????????????????????
at first i thought the same, but based on statement no 1 no matter what numbers you plug in for x and y as long as they satisfy |x+2| = |y+2| the answer will always be -4
for example if x=1 then y=-5, if x=7 then y=-11, if x=-8 then y=4.. x+y will always be -4. The numbers cant be x=y since xy < 1 (statement no 1)
hope this helps bro
i believe that for statement 2 to be correct, n has to be either negative or a decimal. so statement 2 would be sufficient as well?
oops, just got it. my bad.
Mr. Gill can you give me a hint for the problem t 42:00, how n = 0 -1 02 etc only from statement 1?
sorry it was n = 0, -1, -2 etc
Prathap LLN
Got it.....sir....you need not give explanation
In q3) x/y>1 u took x=3,y=2 then it satisfies ...in case of vicecersa it will not.so statement 1 is true.how could b statement 2 true
That was a mistake however still statement (2) won't matter as n can be -1, -2 and so on....
Great video!Helped a lot. Thank you :)
I dont think the answer of the question at 40:30 is correct, it should be E. The question is asking what is the definite value of x+y which is not obtained
I am sure too it is E. X+Y yields multiple answers. I don't what this guy is smoking while he was explaining.
jammerules80 x + y = 4 when the signs are opposite.
He wasn't smoking anything just trying to help morons like you who can't put their thoughts straight and in decent manner
i think it should be (B) because for any values given by statement 2,the value of x+y is always a 4 but statement 1 is not sufficient because the value of x+y cant be determined with the statement 1 n if u put the values of x and y (-x n +y once n then +x and -y),u will get different values of x+y satisfying |x+2|=|y+2|
Ryann good one bro 😀😀😀😀
Where are the videos for EQUATIONS chapter?
Please I'm not really clear with the answer of |x+2|=|Y+2| . Please will the answer not be A given that in statement two, y could range from 1 to -infinity? If y
Hi Pushpinder,
The answer to the question ending at 42:00 is E, not D. x+y is either 4 or -4 and the two conditions each can result in both 4 and -4 by assuming different values for x and y. Therefore, we cannot reach a certain answer (eirher 4 or -4) for this question and therefore the answer is D. Take a look at it please.
Thank you for your comment. In both cases the value of x+y is -4. The answer is D.
That's true. I watched it again
U made mistake in -3/-2>1 in this we can cancel Negative sine
At 36:10 x>-1 so, x might be -0.5 no?
exactly my point!
was waiting for this since a long time....
gill saab nice voice
why so long
2 mistakes,
First one,
at 45 minute mark, the answer for the question would change. As 1/|n|
At 40:30, it is not a mistake. You can check the solution at:
gmatclub.com/forum/x-2-y-2-what-is-the-value-of-x-y-172994.html
For 45:00, n can be -5 as well.
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got it... sorry sir... my mistake
tq
algreba:)))))
karan johar
Please stop saying "quality information".