Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
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.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
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 Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart 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 563 reviewsTarget Test Prep

a DS question but what if we were to solve

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 100
Joined: Sat Sep 11, 2010 6:57 pm
Thanked: 2 times
by shoot4greatness » Tue May 31, 2011 12:34 pm
the inflation index for the year 1989 relative to the year 1970 was 3.56, indicating that, on the average, for each dollar spend in 1970 for goods, $3.56 had to be spent for the same goods in 1989. If the price of Model K mixer increased precisely according to the inflation index, what was the price of the mixer in 1970?

1. the price of the Model K mixer was $102.40 more in 1989 than in 1970

2. the price of the model K mixer was $142.40 in 1989

The answer is d

if we were to solve, for instance 1, do we divide the 102.40 by the inflation index to solve for the price in 70 or do we just leave the increase as is?
Last edited by shoot4greatness on Tue May 31, 2011 2:59 pm, edited 1 time in total.
Top
Join the discussion
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 40
Joined: Tue Jan 18, 2011 5:14 amFollowed by: 2 members
Location: Bangalore
Thanked: 3 times

by bajwa2307 » Tue May 31, 2011 12:53 pm
are you sure that the answer is c?

let price in 1970 be x
let price in 1989 be y

so by statement 1, we have

y - x = 102.40

now we know that 3.56x = y

so substitute the value of y in equation and solve for X, hence 1 is sufficient

by using statement 2, we have

y = 142.40

use the relation, 3.56x = y

substitute the value of y and solve for x, so 2 alone is also sufficient

I think the answer should be D or am I doing something wrong here?
Verbal is testing my patience
Top
Join the discussion
Senior | Next Rank: 100 Posts
Posts: 97
Joined: Sun May 15, 2011 9:19 amFollowed by: 1 member
Thanked: 18 times

by SoCan » Tue May 31, 2011 1:33 pm
Answer is definitely D, not C

x=price in 1970

1) x=(x+102.4)/3.56
3.56x=x+102.4
2.56x=102.4
x=40

2) x=142.40/3.56
x=40

What source gave you C?
Top
Join the discussion
Master | Next Rank: 500 Posts
Posts: 100
Joined: Sat Sep 11, 2010 6:57 pm
Thanked: 2 times

by shoot4greatness » Tue May 31, 2011 2:57 pm
Sorry typo yes its d
Top
Join the discussion
Junior | Next Rank: 30 Posts
Posts: 25
Joined: Wed Feb 13, 2013 9:25 pm
Thanked: 2 times

by serendipiteez » Sun May 26, 2013 4:40 am
My gut feel was "How does knowing what it increased by tell me anything about the original price?" and then I moved on. But clearly, there's an algebraic solution.

Generally speaking, if we know the difference in prices between two dates like this example, can we always solve and get an answer?

I'm trying to understand whether this is just a special case where it just worked out or can this be taken as a general rule?
Top
Join the discussion