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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

130-point score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Powers of numbers

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 106
Joined: Wed Feb 04, 2009 6:09 am
Location: Louisville, KY
Thanked: 8 times
by marcusking » Wed Feb 11, 2009 11:53 am
If , (0.063*10^w)/(.0007*10^k) = 9*10^5 then w –k=

(A) 3 (B) 4(C) 5(D) 6(E) 71.

I keep getting D. 6

But the OA is B. 4

I think the answer given is wrong. I've tried plugging in numbers and I affirm my answer but maybe I'm approaching it wrong.
Last edited by marcusking on Wed Feb 11, 2009 12:34 pm, edited 1 time in total.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 392
Joined: Thu Jan 15, 2009 12:52 pm
Location: New Jersey
Thanked: 76 times

by truplayer256 » Wed Feb 11, 2009 12:29 pm
The OA is incorrect... The correct answer is (C.)5. Here's why:
.063=6.3/100
.0007=7/10000
So, 6.3/100/(7/10000)=6.3/100*10000/7=6.3*100/7=6300/7=90
(90)(10^w-k)=9*10^6
Divide by 90 on both sides.
10^w-k=10^6*10^-1
10^w-k=10^6-1
10^w-k=10^5
w-k=5
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 3225
Joined: Tue Jan 08, 2008 2:40 pmFollowed by: 614 members
Location: Toronto
Thanked: 1710 times
GMAT Score:800

Re: Powers of numbers

by Stuart@KaplanGMAT » Wed Feb 11, 2009 12:30 pm
marcusking wrote:If , (0.063*10^w)/(.0007*10^k) = 9*10^5 then w –k=

(A) 3 (B) 4(C) 5(D) 6(E) 71.
(0.063*10^w)/(.0007*10^k) = 9*10^5

Let's break the left side up into two fractions:

(0.0630)/(0.0007) * 10^w/10^k = 9*10^5

multiplying the first fraction by 10000/10000, we get:

630/7 * 10^w/10^k = 9*10^5

90 * 10^w/10^k = 9*10^5

10^w/10^k = 9*10^5/9*10^1

10^(w-k) = 10^(5-1)
w - k = 5 - 1
w - k = 4

[edited after original question was edited]
Last edited by Stuart@KaplanGMAT on Wed Feb 11, 2009 12:58 pm, edited 1 time in total.
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 106
Joined: Wed Feb 04, 2009 6:09 am
Location: Louisville, KY
Thanked: 8 times

by marcusking » Wed Feb 11, 2009 12:36 pm
Thank you both for your answers, I didn't enter the equation correctly it should have been = 9*10^5 I have made the correction in bold.

But the same principal applies and I get the correct answer after seeing how you've solved it. I made the mistake of thinking .063/.0007 = 9 when really it is 90 thus throwing off the power I needed to multiply by.

Thanks again!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1