2 of 2 that got away

Expert replies

SoftwareDrone: Junior | Next Rank: 30 Posts; Posts: 22; Joined: Thu Jun 21, 2012 1:25 pm; Location: San Jose, CA; GMAT Score:430

by SoftwareDrone » Sun Aug 05, 2012 5:30 pm

After completing the GMAT Prep Now video sessions, I am happy to report that I scored a 640 on my practice test today. This is great, considering my first (and only so far) attempt at the GMAT (before the GMAT Prep Now videos) yielded a 430. There were two math problems in particular that didn't seem so difficult at first glance, yet I cannot seem to push through. The second one is:

10^8 - 10^2 / 10^7 - 10^3.

I thought to do this: 10^2(10^6 - 1) / 10^3(10^4 - 1), but cannot figure out how to go further.
Please help me O Gurus.

Source: Beat The GMAT — Problem Solving | Sun Aug 05, 2012 5:30 pm

GMATGuruNY: GMAT Instructor; Posts: 15539; Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members; Location: New York, NY; Thanked: 13060 times; GMAT Score:790

by GMATGuruNY » Sun Aug 05, 2012 7:22 pm

The value of (10^8-10^2)/(10^7-10^3) is closest to which of the following?

a)1
b)10
C)10^2
d)10^3
e)10^4

Please always post the answer choices.

Since this question asks for an APPROXIMATION, 10² and 10³ can safely be ignored here: these values are VERY, VERY SMALL relative to 10� and 10�.
Thus:
(10� - 10²) / (10� - 10³) ≈ 10�/10� = 10.

The correct answer is B.

Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

SoftwareDrone: Junior | Next Rank: 30 Posts; Posts: 22; Joined: Thu Jun 21, 2012 1:25 pm; Location: San Jose, CA; GMAT Score:430

by SoftwareDrone » Sun Aug 05, 2012 8:19 pm

Sorry about that. I would have written down the answer choices had I had them. I only had the problem from scribbling it down during the test.
Good point about the relative size of the numbers.
Thanks!

Featured schoolRound 2 closes Jan 7, 2027 53 days left

Chicago Booth

Since 1982, 10 Booth faculty members have received the Nobel Prize in Economic Sciences, more than any other business school.

#3
U.S. News rank: $175,000
Median base salary: 670
Average GMAT Focus: 635
Students in the class

Apply to Booth Visit chicagobooth.edu See the full profile

Photo: Warren LeMay, CC BY-SA 2.0

GMAT Course Reviews

563 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (563 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review