GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 19 Feb 2019, 13:11

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Events & Promotions

Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
• Free GMAT Prep Hour

February 20, 2019

February 20, 2019

08:00 PM EST

09:00 PM EST

Strategies and techniques for approaching featured GMAT topics. Wednesday, February 20th at 8 PM EST

February 21, 2019

February 21, 2019

10:00 PM PST

11:00 PM PST

Kick off your 2019 GMAT prep with a free 7-day boot camp that includes free online lessons, webinars, and a full GMAT course access. Limited for the first 99 registrants! Feb. 21st until the 27th.

During a special promotion, a certain filling station is offering a 10

Author Message
TAGS:

Hide Tags

Intern
Joined: 05 Nov 2011
Posts: 15
Location: France, Metropolitan
During a special promotion, a certain filling station is offering a 10  [#permalink]

Show Tags

20 Feb 2015, 02:04
2
12
00:00

Difficulty:

75% (hard)

Question Stats:

62% (02:39) correct 38% (02:50) wrong based on 231 sessions

HideShow timer Statistics

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%
Math Expert
Joined: 02 Sep 2009
Posts: 52971
Re: During a special promotion, a certain filling station is offering a 10  [#permalink]

Show Tags

20 Feb 2015, 03:01
2
Stardust Chris 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%

Kim purchased 20 gallons of gas. She paid for 10 + 0.9*10 = 19 gallons, so the overall discount she got was 1/20 = 5%.

Isabella purchased 25 gallons of gas. She paid for 10 + 0.9*15 = 23.5 gallons, so the overall discount she got was 1.5/25 = 6%.

6 is 6/5*100 = 120% of 5.

_________________
Math Expert
Joined: 02 Aug 2009
Posts: 7334
During a special promotion, a certain filling station is offering a 10  [#permalink]

Show Tags

20 Feb 2015, 21:48
2
1
Stardust Chris 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%

hi,
just take the discount to be 1 unit on every gallon above 10..
kim saved 10 on 20 gallons or$$\frac{1}{2}$$per gallon...
isabella saved 15 on 25 gallons or $$\frac{15}{25}=\frac{3}{5}$$per gallon..
%=$$100*(\frac{3}{5})/(\frac{1}{2})=\frac{600}{5}=120%$$...ans B
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html
4) Base while finding % increase and % decrease : https://gmatclub.com/forum/percentage-increase-decrease-what-should-be-the-denominator-287528.html

GMAT Expert

Intern
Joined: 21 Oct 2015
Posts: 46
GMAT 1: 620 Q47 V28
Re: During a special promotion, a certain filling station is offering a 10  [#permalink]

Show Tags

15 Apr 2016, 01:35
Hi Bunuel,

Thanks for the explanation. A small clarification required though..

You have applied the specified discount on #Units of Gallons. Though it doesn't matter but I chose to look at the given discount in terms of Price/Gallon ($1/G) and then followed the same approach. I usually take time on percent questions if they're of 700+ level. Do you see any obvious flaw in my approach? I could work on some particular concept files if you think that may help me provide a direct and efficient approach to percent problems. Accuracy is moderate on higher level percent question but time is of concern. This includes my accuracy on Manhattan CATS. Hari Bunuel wrote: Stardust Chris 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% Kim purchased 20 gallons of gas. She paid for 10 + 0.9*10 = 19 gallons, so the overall discount she got was 1/20 = 5%. Isabella purchased 25 gallons of gas. She paid for 10 + 0.9*15 = 23.5 gallons, so the overall discount she got was 1.5/25 = 6%. 6 is 6/5*100 = 120% of 5. Answer: D. Posted from my mobile device Senior RC Moderator Status: Preparing GMAT Joined: 02 Nov 2016 Posts: 2241 Location: Pakistan GPA: 3.39 During a special promotion, a certain filling station is offering a 10 [#permalink] Show Tags 08 Mar 2017, 09:19 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% _________________ New Project RC Butler 2019 - Practice 2 RC Passages Everyday Final days of the GMAT Exam? => All GMAT Flashcards. This Post Helps = Press +1 Kudos Best of Luck on the GMAT!! Math Expert Joined: 02 Sep 2009 Posts: 52971 Re: During a special promotion, a certain filling station is offering a 10 [#permalink] Show Tags 08 Mar 2017, 09:32 SajjadAhmad 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% Please refer to the discussion above. _________________ Director Joined: 13 Mar 2017 Posts: 703 Location: India Concentration: General Management, Entrepreneurship GPA: 3.8 WE: Engineering (Energy and Utilities) Re: During a special promotion, a certain filling station is offering a 10 [#permalink] Show Tags 23 Aug 2017, 02:37 Stardust Chris 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% Let R be the fixed rate of the gas per gallon. So for first 10 gallon, rate = 10 R After this the gas will be available at 10 percent discount. Kim purchased 20 gallon of gas. So, price = 10R +.9*10 R = 19R Discount per gallon = 1/20 Isabella purchased 25 gallons of gas. So, price = 10 R + .9*15 R = 22.5 R Discount per gallon = 1.5/25 = 3/50 So, percentage of Isabella‟s total per-gallon discount w.r.t Kim‟s total per-gallon discount = (3/50)/(1/20) *100 = 120% Answer D _________________ CAT 2017 (98.95) & 2018 (98.91) : 99th percentiler UPSC Aspirants : Get my app UPSC Important News Reader from Play store. MBA Social Network : WebMaggu Appreciate by Clicking +1 Kudos ( Lets be more generous friends.) What I believe is : "Nothing is Impossible, Even Impossible says I'm Possible" : "Stay Hungry, Stay Foolish". Target Test Prep Representative Status: Founder & CEO Affiliations: Target Test Prep Joined: 14 Oct 2015 Posts: 4933 Location: United States (CA) Re: During a special promotion, a certain filling station is offering a 10 [#permalink] Show Tags 25 Aug 2017, 10:07 Stardust Chris 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% 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.

_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Intern
Joined: 26 Oct 2016
Posts: 26
During a special promotion, a certain filling station is offering a 10  [#permalink]

Show Tags

26 Aug 2017, 08:16
shashankism wrote:
Stardust Chris 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%

Let R be the fixed rate of the gas per gallon.
So for first 10 gallon, rate = 10 R

After this the gas will be available at 10 percent discount.

Kim purchased 20 gallon of gas. So, price = 10R +.9*10 R = 19R
Discount per gallon = 1/20

Isabella purchased 25 gallons of gas. So, price = 10 R + .9*15 R = 22.5 R
Discount per gallon = 1.5/25 = 3/50

So, percentage of Isabella‟s total per-gallon discount w.r.t Kim‟s total per-gallon discount = (3/50)/(1/20) *100 = 120%

I think you made a typo error in the highlighted portion, It should be 23.5 R
Manager
Joined: 03 May 2014
Posts: 158
Location: India
WE: Sales (Mutual Funds and Brokerage)
During a special promotion, a certain filling station is offering a 10  [#permalink]

Show Tags

07 Sep 2017, 19:50
Let the cost of fuel be $10 per gallon. Kim First, 10 gallons price=10*$10=$100 2nd 10 gallon Price=10*$9=90 (Discount of 10% or $1 after first 10 gallons) Total Paid$190
In case there would have been no discount than amount paid would have been $200(20*10) Savings$10.
Total savings on Total fuel purchased=$$\frac{10}{20}$$=$$\frac{1}{2}$$
Isabella
First 10 gallon price=10*$10=100 2nd 15 gallon Price=15*$9=135 (Discount of 10% or $1 after first 10 gallons) Total Paid$235
In case there would have been no discount than amount paid would have been $250(25*$10)
Savings \$15.
Total savings on Total fuel purchased=$$\frac{15}{25}$$=$$\frac{3}{5}$$

% of $$\frac{Isabella}{Kim}$$= $$\frac{3}{5}$$÷$$\frac{1}{2}$$=$$\frac{6}{5}$$=1.2*100=120%
Non-Human User
Joined: 09 Sep 2013
Posts: 9851
Re: During a special promotion, a certain filling station is offering a 10  [#permalink]

Show Tags

20 Oct 2018, 06:08
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: During a special promotion, a certain filling station is offering a 10   [#permalink] 20 Oct 2018, 06:08
Display posts from previous: Sort by