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
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
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.

715+ 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.

Integers equally spaced on a line - help?

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 23
Joined: Tue Jul 27, 2010 12:26 pm
Location: Washington, DC
GMAT Score:700
by saritalr » Mon Aug 09, 2010 10:17 am
This problem threw me off the first time around. Now I understand how to set up the equation but I'm having trouble with the algebra. First the problem:


[Image of 4 integers A, B, C, and D on a number line]
The integers A, B, C, and D shown on the number line above are all equally spaced. If C and D are equal to 5^12 and 5^13, respectively, what is the value of A?
  • 1. 5^11
    2. 5^10
    3. -5^12
    4. (-7)5^12
    5. (-12)5^13

I can set up the equation: [spoiler]D minus three times the difference between C and D (or) 5^13 - 3(5^13-5^12) = A.[/spoiler] But after that, I'm lost with the algebra.

Below is the algebra for the right answer:
[spoiler]5^13 - 3(5^13 - 5^12)
5^13 - 3[5^12(5 - 1)]
5^13 - 3(5^12)(4)
5(5^12)- 12(5^12)
(-7)5^12

The correct answer is D.[/spoiler]

Can someone explain what operations are taking place in the first 2 lines?

Thanks in advance.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 1460
Joined: Tue Dec 29, 2009 1:28 amFollowed by: 7 members
Thanked: 135 times

by selango » Mon Aug 09, 2010 10:29 am
The integers are equally spaced.

A+x=B

B+x=C

C+x=D

x is an difference between 2 integers.

Now C=5^12 and D=5^13

5^12+X=5^13

x=5^13-5^12=5^12(5-1)=4.5^12

Since the integers are equally spaced.

A+3x=D

A+3(4.5^12)=5^13

A+12.5^12=5^13

A=5^13-12.5^12=5^12(5-12)

=-7.5^12

Hope this clarify.
--Anand--
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 29
Joined: Tue Jun 29, 2010 5:23 am
Thanked: 3 times

by nicolezl » Mon Aug 09, 2010 10:44 am
saritalr wrote:5^13 - 3(5^13 - 5^12)
5^13 - 3[5^12(5 - 1)]
5^13 - 3(5^12)(4)
5(5^12)- 12(5^12)
(-7)5^12

The correct answer is D.

Can someone explain what operations are taking place in the first 2 lines?

Thanks in advance.
In the second line, you factor out 5^12 from (5^13 - 5^12), which gives you 5^12*(5-1).

Does that help?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1460
Joined: Tue Dec 29, 2009 1:28 amFollowed by: 7 members
Thanked: 135 times

by selango » Mon Aug 09, 2010 10:45 am
saritalr,

Your approach is also same and correct..

[spoiler]5^13 - 3(5^13-5^12) = A

=5^13-3.5^12(5-1)

=5^13-12.5^12

=5^12(5-12)=-7.5^12[/spoiler]
--Anand--
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 23
Joined: Tue Jul 27, 2010 12:26 pm
Location: Washington, DC
GMAT Score:700

by saritalr » Mon Aug 09, 2010 10:55 am
selango wrote:
A=5^13-12.5^12=5^12(5-12)

=-7.5^12
Thanks Selango. Can you explain the above line - are you factoring something out?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 23
Joined: Tue Jul 27, 2010 12:26 pm
Location: Washington, DC
GMAT Score:700

by saritalr » Mon Aug 09, 2010 10:56 am
nicolezl wrote:
In the second line, you factor out 5^12 from (5^13 - 5^12), which gives you 5^12*(5-1).

Does that help?
Very helpful! Just what I needed - thank you!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1460
Joined: Tue Dec 29, 2009 1:28 amFollowed by: 7 members
Thanked: 135 times

by selango » Mon Aug 09, 2010 4:33 pm
saritalr wrote:
selango wrote:
A=5^13-12.5^12=5^12(5-12)

=-7.5^12
Thanks Selango. Can you explain the above line - are you factoring something out?
A=5^13-12.5^12

Here I am taking 5^12 as common factor.

=5^12(5-12)

=5^12(-7)

Hope this clarify.
--Anand--
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1