BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Hard Math Questions

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 16
Joined: Fri Feb 23, 2007 9:47 pm

Hard Math Questions

by HW » Mon Apr 16, 2007 3:21 pm
Hello,

I'm studying from the OG 10th edition. I am having a tough time on the hard math questions(mostly on the number properties ones). I need a 600-620 on the test. Are these types of questions in the 700+ level or not? Should I postpone the test(date set right now is April 28th) to get a better grasp of these number properties or should you only try to learn the hard questions if aiming for a 700+?

Thanks.
Top
Source: — Quantitative Reasoning |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2228
Joined: Wed Dec 27, 2006 3:28 pm
Location: Montreal, Canada
Thanked: 639 times
Followed by:694 members
GMAT Score:780

by Stacey Koprince » Mon Apr 16, 2007 11:06 pm
Hi, HW - it's a little difficult for me to respond precisely to your query because I can't tell what you mean by "hard." The book doesn't tell you the difficulty levels of the questions - it just says that, generally, the later questions in a chapter are harder. But it's not a hard and fast rule, and I don't know at what point in the mix they are "too hard" for you.

Generally, yes, if you're going for a 600-620, you don't need to worry about the very hardest questions in there. (At least, you don't need to worry about getting them right - you'll still see some, but the computer will expect you to get them wrong, and that is what you want to do. Promptly. So that you don't waste time on questions you can't do and then cost yourself points on later questions that you can do but don't have time to get to.)
Please note: I do not use the Private Messaging system! I will not see any PMs that you send to me!!

Stacey Koprince
GMAT Instructor
Director of Online Community
Manhattan GMAT

Contributor to Beat The GMAT!

Learn more about me
Top
Junior | Next Rank: 30 Posts
Posts: 16
Joined: Fri Feb 23, 2007 9:47 pm

by HW » Tue Apr 17, 2007 7:33 am
Thanks for the reply.

There is a grid(that I found on this website) that classifies questions as easy,medium, and hard for the 10th edition. The questions that I have no clue about are the hard number property ones.

To give you an example from the 10th edition, Which of the following is the least positive integer that is divisiblle by 2,3,4,5,6,7,8, and 9? Whenever I encounter questions such as these I'm always thinking that how am I supposed to know and how is this relevant to anything in life. Is there any source that can help you with questions such as these or should I not worry since my goal is just 600-620?
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2228
Joined: Wed Dec 27, 2006 3:28 pm
Location: Montreal, Canada
Thanked: 639 times
Followed by:694 members
GMAT Score:780

by Stacey Koprince » Tue Apr 17, 2007 10:32 am
Oh, right - I forgot about that grid. That's not from the OG though - I think someone just assessed it and made best guesses.

For number properties, I would try to learn that stuff as thoroughly as you can just b/c that topic shows up all the time. The last time I took the test 12 of my 37 math questions were number properties - or about 1/3 of all questions.

For the example you give:
Which of the following is the least positive integer that is divisible by 2,3,4,5,6,7,8, and 9?

You basically want to break these down to prime and figure out the minimum you need for each one.

2: need a 2
3: need a 3
4: need two 2's (and already have one, so only need one more 2)
5: need a 5
6: need a 2 and a 3 (and we already have these, so can ignore)
7: need a 7
8: need three 2's (and already have two, so only need one more 2)
9: need two 3's (and already have one, so only need one more 3)

so that's:
2*3*2*5*7*2*3 = (2*2*5*2)*(3*7*3) = 40*63 (and then you might be able to just look at the answer choices rather than continuing to multiply this out - but you didn't provide the answers, so have to keep multiplying) = 2520.
Please note: I do not use the Private Messaging system! I will not see any PMs that you send to me!!

Stacey Koprince
GMAT Instructor
Director of Online Community
Manhattan GMAT

Contributor to Beat The GMAT!

Learn more about me
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2228
Joined: Wed Dec 27, 2006 3:28 pm
Location: Montreal, Canada
Thanked: 639 times
Followed by:694 members
GMAT Score:780

by Stacey Koprince » Tue Apr 17, 2007 10:32 am
p.s.

And as to how this is relevant to anything in life? There I can't help you... :)
Please note: I do not use the Private Messaging system! I will not see any PMs that you send to me!!

Stacey Koprince
GMAT Instructor
Director of Online Community
Manhattan GMAT

Contributor to Beat The GMAT!

Learn more about me
Top
Master | Next Rank: 500 Posts
Posts: 135
Joined: Tue Feb 27, 2007 7:21 pm
Thanked: 2 times

by rajesh_ctm » Tue Apr 17, 2007 3:16 pm
Whenever I encounter questions such as these I'm always thinking that how am I supposed to know and how is this relevant to anything in life.


Though you need to be comfortable working with numbers if you are aspiring to be a good manager, I agree these questions are not relevant to your life. What is relevant to things in your life cannot be directly tested. You might learn all the theoretical stuff and ace the exams, but still fail to apply them in your real life.

In fact many things you have learnt since childhood are not relevant to your life. But learning those has improved your intellect. What is relevant to your life is your learnability rather than the things learnt. GMAT probably tries to test the learnability rather than the learnt.
Top

GMAT/MBA Expert

User avatar
Site Admin
Posts: 6778
Joined: Mon Feb 13, 2006 8:30 am
Location: Los Angeles, CA
Thanked: 1249 times
Followed by:994 members

by beatthegmat » Tue Apr 17, 2007 4:32 pm
rajesh_ctm wrote:
Whenever I encounter questions such as these I'm always thinking that how am I supposed to know and how is this relevant to anything in life.


Though you need to be comfortable working with numbers if you are aspiring to be a good manager, I agree these questions are not relevant to your life. What is relevant to things in your life cannot be directly tested. You might learn all the theoretical stuff and ace the exams, but still fail to apply them in your real life.

In fact many things you have learnt since childhood are not relevant to your life. But learning those has improved your intellect. What is relevant to your life is your learnability rather than the things learnt. GMAT probably tries to test the learnability rather than the learnt.
I agree that these kinds of questions may not be relevant to life--but they are certainly relevant to business school. I've heard that some schools have a reputation as being heavily quantitative, and brushing up on your math via GMAT is one step towards preparing yourself for the curriculum at b-school.
Beat The GMAT | The MBA Social Network
Community Management Team

Research Top GMAT Prep Courses:
https://www.beatthegmat.com/gmat-prep-courses

Research The World's Top MBA Programs:
https://www.beatthegmat.com/mba/school
Top
Junior | Next Rank: 30 Posts
Posts: 16
Joined: Fri Feb 23, 2007 9:47 pm

by HW » Tue Apr 17, 2007 9:16 pm
Stuff like percentages/ratios/etc can be relevant to business/business schools. In fact, I'm glad they're tested on the GMAt because it gave me the opportunity to brush up on these topics. I was talking more about prime factorization/geometry...stuff like that. However, as Rajesh mentioned, it may be more of a test on how to take a test than anything.

What really surprised me was the fact that the 10th edition really does not explain concepts like prime factorization, both in the intro and the answer explanations. In fact, I learned more about it here than in the book.

In any case, thanks for your help Stacey.
Top
Post new topic Post Reply
• Page 1 of 1