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

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

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20 Feb 2015, 03:04
2
12
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Difficulty:

65% (hard)

Question Stats:

63% (02:39) correct 37% (02:50) wrong based on 235 sessions

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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: 58396
Re: During a special promotion, a certain filling station is offering a 10  [#permalink]

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20 Feb 2015, 04:01
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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.

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During a special promotion, a certain filling station is offering a 10  [#permalink]

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20 Feb 2015, 22:48
2
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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
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Joined: 21 Oct 2015
Posts: 45
GMAT 1: 620 Q47 V28
Re: During a special promotion, a certain filling station is offering a 10  [#permalink]

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15 Apr 2016, 02:35
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 Joined: 02 Nov 2016 Posts: 4136 GPA: 3.39 During a special promotion, a certain filling station is offering a 10 [#permalink] ### Show Tags 08 Mar 2017, 10:19 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% _________________ Math Expert Joined: 02 Sep 2009 Posts: 58396 Re: During a special promotion, a certain filling station is offering a 10 [#permalink] ### Show Tags 08 Mar 2017, 10:32 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 Affiliations: IIT Dhanbad Joined: 13 Mar 2017 Posts: 728 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, 03:37 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: 8117 Location: United States (CA) Re: During a special promotion, a certain filling station is offering a 10 [#permalink] ### Show Tags 25 Aug 2017, 11:07 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.

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During a special promotion, a certain filling station is offering a 10  [#permalink]

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26 Aug 2017, 09:16
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
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Posts: 151
Location: India
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During a special promotion, a certain filling station is offering a 10  [#permalink]

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07 Sep 2017, 20:50
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%
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Re: During a special promotion, a certain filling station is offering a 10  [#permalink]

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20 Oct 2018, 07:08
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Re: During a special promotion, a certain filling station is offering a 10   [#permalink] 20 Oct 2018, 07:08
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