GMAT Quant Concepts by Experts' Global | Videos, Exercises, More...!

Question

Dear Friends,

Hope everyone is awesome!

Breathing GMAT and MBA applications for ~10 years now, I wish to take my concepts to a larger audience. What better than GMAT Club?!

Here is the theme of this thread...

- I shall be posting a concept (generally explained over a video) together with a set of problems, based on the concept.

- The emphasis will be on concepts that students generally struggle with or the concepts that have not been covered comprehensively in the standard books (but are tested on GMAT).

- I encourage the students on the thread to participate and solve the questions (these shall generally be original questions, freshly baked for you by Experts' Global). Reply with your set of answers.

- I shall return to give the correct answers/explanations. I will be happy to solve any queries.

- I encourage other experts and aspirants on the forum to bring up their concepts.

Gradually, we shall develop a rich repertoire of all GMAT concepts. A resource that shall continue to help the GMAT aspirants in the times to come.

Beginning with quant, we will gradually have similar threads for all sections of GMAT.

All the best friends!

Regards,
Maxximus!

Maxximus · Answer

Friends,

Here is the first concept:

1. Inequations on GMAT

The topic is vast and I will be covering it in ~4 parts. Today's concept is on...

1.1 Factorization Based Inequations Questions

The following video (~8 minutes) shall explain the concept in great detail. Please watch the video carefully and solve the problems in it.

https://www.youtube.com/watch?v=zakbpprsj7s&t=11s

Once done, please solve the following, five questions. I shall need five answers (say, BCEAD) from every participant.

-----------------------
1. If (3x^2) > 2x, which of the following specifies all the possible values of x?

A. x < 0
B. x > 2/3
C. x > 3/2
D. 0 < x < 2/3
E. x < 0 and x > 2/3

2. If x^2 + 6x > 27, which of the following specifies all the possible values of x?

A. x > 3
B. x < -9
C. -9 < x < 3
D. x > 3 and x < -9
E. x > 9 and x < -3

3. If [(x^2 + 7x – 30) / x] ≥ 0, which of the following specifies all the possible values of x?

A. x ≥ 3
B. x ≥ -10
C. -10 ≤ x < 0
D. x ≥ 3 and -10 ≤ x ≤ 0
E. x ≥ 3 and -10 ≤ x < 0

4. How many of the integers that satisfy the inequality [(x-1)(x+2)(x+3)] ≤ 0 are greater than -5?

A. 4
B. 5
C. 6
D. 7
E. More than 7

5. How many of the integers that satisfy the inequality [(x-7)(x+2)(x+6) / x(x+4)] ≥ 0 are less than 10?

A.5
B.7
C.9
D.11
E.More than 11

-----------------------

Hope this helps, guys. All the best!

Regards,
Maxximus!

SHire2709 · Answer

Hey,

Thanks Maxximus, 
This is interesting concept and look forward to more.

I will watch this video and get back with answers.

Sent from my iPhone using GMAT Club Forum

HKD1710 · Answer

Hi  maxximus ,

Thank you for starting this helpful thread. Here is the answer series  EDECB

Maxximus · Answer

Welcome to the thread, SHire and HKD1710!

Good job HKD1710. I would be posting the detailed explanations later in the day. In the meanwhile, you may want to watch the following video...

Using answer choices in Geometry questions (~13 Minutes)
https://www.youtube.com/watch?v=xZSMzJ_sT6s

Regards,
Maxximus!

attari92 · Answer

The answer sequence would be -EDECC

Maxximus · Answer

Dear Anviksha and Attari,

Welcome to the thread!

The correct choice of answers is EDECB.

Kudos to HKD for getting all answers correct! Congrats!

Other members had one or more answers incorrect. Please view the detailed explanations in the following video:

https://www.youtube.com/watch?v=ynnQmwyCvOk

Hope this helps.

Next concept, coming up in a few hours.

All the best!
Maxximus!

Maxximus · Answer

Friends,

Here is the next concept:

1.2 Modulus Based Inequations Questions

The following video (~8 minutes) shall explain the concept in great detail. Please watch the video carefully and solve the problems in it.

https://youtu.be/OO6cSBpNDhg

Once done, please solve the following, five questions. I shall need five answers (say, BCEAD) from every participant.

-----------------------
If a = |b|, which of the following must be true?

I. |a| = b
II. a^2 = b^2
III. a^3 = b^3

A. I only
B. II only
C. III only
D. I and II only
E. II and III only

2. If |10-3x| < 4, which of the following represents the correct range of values of x?

A. -14/3 < x < -2
B. -14/3 < x < 2
C. 2 < x < 14/3
D. x > 2 or x < 14/3
E. x < 2 or x > 14/3

3. If |x+1| > 2x-1, which of the following represents the correct range of values of x?

A. x < 0
B. x < 2
C. -2 < x < 0
D. -1 < x < 2
E. 0 < x < 2

4. If |3-x| < x+5, which of the following may be true about x?

I. x > -1
II. x < 2
III. x < -2

A. I only
B. II only
C. I and II only
D. I and III only
E. I, II, and III

5. Is x > 1?

1) |2x+5| = 2 - x
2) |x - 12| = 12 - 3x

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

-----------------------

Hope this helps, guys. All the best!

Regards,
Maxximus!

HKD1710 · Answer

Hi  maxximus ,

In 1st question, Considering  a2, b2, a3 and  b3  as  a^2, b^2, a^3 and  b^3  respectively (Please update the same in question, if that is the case), Here is the answer series:
 BCBCA

attari92 · Answer

Has the sequence for the answer options is BCDAD in the second set of questions ? probably there should have been some correction needed in question 1 as the exponent (if it may so ) is misplaced.

Maxximus · Answer

Hello HKD, Thanks for pointing the typo. I corrected that. Hey Attari, Please solve the last three questions again. You are missing something

All the best!

bb · Answer

Moving this to a better forum location.

Posted from my mobile device

flname · Answer

thanks for starting this. looking forward to continue and participate in this thread as and when the concepts progress. thank you.

Srikapardhi

Maxximus · Answer

Thanks BB. Friends, The correct set of answers for those five questions is- BCBCA. Please find detailed explanations on the following link: https://youtu.be/slSogS7Fv8s Regards, Maxximus

sheisify · Answer

thanks for this thread maxximus, inequations have been a sore point for me in quant. 
Cant wait for the next concept...

HKD1710 · Answer

After we learnt the concept, more practice is required. I use the following URL to get more questions for practice:

https://gmatclub.com/forum/viewforumtags.php

I am also waiting for more questions and videos link posted by maximus :D

attari92 · Answer

IMO : BCBAD
ques no. 4. |3-x| < x+5 would give x lies in the range of either -1<x<3 or x>3 => option A
QUES NO. 5.
1ST statement would give x=-1 or -7 both less than 1 -> sufficient
2nd statement would give x= 0 again a confirm no and hence sufficient and that implies option D

Maxximus · Answer

Hello Friends,

Regret that I have been missing in action for a few days. Busy with our annual event. I will be back tomorrow with the next concept. Shall also sort the pending queries then.

Please bear with me.

Cordially,
Maxximus.

Maxximus · Answer

Hi, The following video shall explain it... https://youtu.be/slSogS7Fv8s Regards, Maxximus

Maxximus · Answer

Hello Friends!

Regret my long absence.

Here is the next concept.

1.3 Inequations questions based on -1 < x < 1 range

The following video (~20 minutes) shall explain the concept in great detail. Please watch the video carefully and solve the problems in it.
https://youtu.be/fMFNu2-P_74

Once done, please solve the following, five questions. I shall need five answers (say, BCEAD) from every participant.

-----------------------
1. If x ≠ 0, is |x| = x?

(1) 1/x < 1
(2) 1/x > x

2. Is 0 < x < 1?

(1) 1/x > x
(2) x2 < x

3. Which of the following can never be true?

I. x^-1 < x < x^2 < x^4
II. x^3 < x < x^2 < x^4
III. x^-1 < x < x^-2 < x^-3

A. I only
B. II only
C. III only
D. I and III only
E. II and III only

4. If x,y,z > 0 and x > y > z, which of the following can be true?

I. √x > √z > y
II. √z > √x > y
III. x > √z > y

A. I only
B. II only
C. I and II only
D. I and III only
E. I, II, and III

5. Is x > y?

1) x/2 = y^2
2) x > 0.5

-----------------------

Hope this helps, guys. All the best!

Regards,
Maxximus!

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