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

During a special promotion, a certain filling station is off

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Moderator
Posts: 7187
Joined: Thu Sep 07, 2017 4:43 pmFollowed by: 23 members
by BTGmoderatorDC » Thu Dec 06, 2018 3:54 pm
Timer
00:00
Your answer
Difficulty–

right wrong

Pick an answer to see how members did

During a special promotion, a certain filling station is offering a 10 percent discount on gas purchased after the first 10 gallons. If Kim purchased 20 gallons of gas, and Isabella purchased 25 gallons of gas, then Isabella‟s total per-gallon discount is what percent of Kim‟s total per-gallon discount?

(A) 80%

(B) 100%

(C) 116.7%

(D) 120%

(E) 140%

OA D

Source: Princeton Review
Top
Join the discussion
Source: — Problem Solving |
Newbie | Next Rank: 10 Posts
Posts: 7
Joined: Thu Dec 06, 2018 7:38 am

reply

by Iakgmat » Thu Dec 06, 2018 6:27 pm
Not too sure about this approach... but..
Let P be the price per gallon
Kim = 10P+0.9(10P) = 19P (versus 20P originally)
Isabelle = 10P+0.9(15P) = 22P (versus 25P originally)

Thus Kim has a discount of $$\frac{1}{20}P$$
Isabelle has a discount of $$\frac{3}{25}P$$

This corresponds to 5% discount for Kim and 12% discount for Isabelle

Next to calculate the % of Isabelle's discount in terms of % Kim's discount
$$\frac{12-5}{5}$$

Which gives us 140%
Top
Join the discussion

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10391
Joined: Sun Jun 23, 2013 6:38 pmFollowed by: 511 members
Location: Palo Alto, CA
Thanked: 2867 times
GMAT Score:800

by [email protected] » Thu Dec 06, 2018 8:04 pm
Hi All,

We're told that during a special promotion, a certain filling station is offering a 10 percent discount on gas purchased AFTER the first 10 gallons. Kim purchased 20 gallons of gas, and Isabella purchased 25 gallons of gas. We're asked for Isabella's total PER-GALLON DISCOUNT as a percent of Kim's total PER-GALLON DISCOUNT. This question can be approached in a couple of different ways, including by TESTing VALUES.

To start, let's set the price at $1 for 1 gallon gallon of gasoline.

Kim purchased 20 gallons, with the last 10 gallons discounted 10%, meaning that she saved (10)($1)(.1) = $1.00 off of 20 gallons
Isabella purchased 25 gallons, with the last 15 gallons discounted 10%, meaning that she saved (15)($1)(.1) = $1.50 off of 25 gallons

Kim's per-gallon discount is 1/20 = .05; Isabella's per-gallon discount 1.5/25 = 3/50 = .06

Thus, the percent would be .06/.05 = 6/5 = 1.2 = 120%

Final Answer: D

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
Join the discussion

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8246
Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members
Location: Los Angeles, CA
Thanked: 43 times

by Scott@TargetTestPrep » Fri Mar 22, 2019 8:18 am
BTGmoderatorDC wrote:During a special promotion, a certain filling station is offering a 10 percent discount on gas purchased after the first 10 gallons. If Kim purchased 20 gallons of gas, and Isabella purchased 25 gallons of gas, then Isabella‟s total per-gallon discount is what percent of Kim‟s total per-gallon discount?

(A) 80%

(B) 100%

(C) 116.7%

(D) 120%

(E) 140%

OA D

Source: Princeton Review
Let’s assume that the price per gallon of gas is $10. Thus, the discounted price per gallon of gas after the first 10 gallons is 0.9 x 10 = $9. In other words, after the first 10 gallons, each additional gallon has a $1 discount in price.

Now let’s calculate the total discount for each person. Since Kim purchased 20 gallons of gas, the 10 additional gallons (that is, after the initial 10 gallons) will receive a $10 discount, so her total per-gallon discount is 10/20 = $0.50. Since Isabella purchased 25 gallons of gas, the 15 additional gallons (that is, after the initial 10 gallons) will receive a $15 discount, so her total per-gallon discount is 15/25 = $0.60. Therefore, Isabella’s total per-gallon discount is 0.60/0.50 = 6/5 = 1.2 = 120% of Kim’s total per-gallon discount.

Answer: D

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Join the discussion