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02 May 2012, 14:55
5
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Difficulty:

55% (hard)

Question Stats:

64% (01:32) correct 36% (01:36) wrong based on 1708 sessions

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The price of lunch for 15 people was $207.00, including a 15 percent gratuity for service. What was the average price per person, EXCLUDING the gratuity? (A)$11.73
(B) $12.00 (C)$13.80
(D) $14.00 (E)$15.87

[Reveal] Spoiler:
How come the answer is B?

This is how I solved it and got A, which is incorrect.

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03 May 2012, 06:51
3
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enigma123 wrote:
The price of lunch for 15 people was $207 including a 15% gratuity for service. What was the average price per person, EXCLUDING the gratuity? A. 11.73 B. 12 C. 13.8 D. 14 E. 15.87 How come the answer is B? This is how I solved it and got A, which is incorrect.$207 includes 15% gratuity so 0.15 * 207 = 31.05

Price EXCLUDING gratuity = 207 - 31.05 = 175.95

Average price per person = 175.95/15 = 11.73

I'll show You perhaps the most easiest way to solve such problem

As it is a percentage problem so just take the initial price before the gratuity is 100 the as the gratuity is calculated on the final price, so as we assumed the final bill before adding gratuity is 100 so gratuity is 15% of 100 is 15 so the total price of meals is 115 so the given amount i.e 207 is for 115 then we have to calculate for 100 here we go

for 115 207
for 100 x

so by cross multiplication we get 115x=100*207 => x=100*207/110 by simplifying we get x as 180 which is the price of lunch before gratuity so the gratuity is 27 so

as the question ask the average price person excluding gratuity is 180/15=12 so our answer is b

hope its concise and clear .

if u satisfied with my effort don't hesitate to give +1 kudos.

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03 May 2012, 11:56
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Expert's post
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kashishh wrote:
GyanOne wrote:
The mistake you have made is that you have calculated the gratuity on the final amount, instead of finding the amount on which gratuity was charged to get the final amount.

If the amount spent excluding the gratuity was x, then x(1.15) = 207
=> x = 207/1.15 = 180

Then the average price per person = 180/15 = 12

Option (B)

gratuity is charged on final amount then is it not obvious to calculate such as!

just wish to have clarification on the two :
1.) 270 - 15% of 270 = 175.95/ 15 = 11.73

2.) if 115 is 270 then 100 = 180 and 180/15 = 12

is it not the same thing ?

Tip is charged on the bill. Consider this: the bill is $100 and tip is 15% means that total amount paid is 100+15=$115.

The price of lunch for 15 people was $207 including a 15% gratuity for service. What was the average price per person, EXCLUDING the gratuity? A. 11.73 B. 12 C. 13.8 D. 14 E. 15.87 Bill*1.15=$207 --> Bill=$180 --> per person=$180/15=$12. Answer: B. _________________ Kudos [?]: 139528 [3], given: 12794 Manager Joined: 17 Sep 2011 Posts: 190 Kudos [?]: 145 [1], given: 8 The price of lunch for 15 people was$207 including a 15% [#permalink]

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10 May 2012, 02:22
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The solution is :

207 * .15 = 31.05 ==> 207 - 31.05 = 175.95==> 175.95 / 15 = 11.73
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Re: The price of lunch for 15 people was $207 including a 15% [#permalink] Show Tags 14 May 2012, 05:10 enigma123 wrote: The price of lunch for 15 people was$207 including a 15% gratuity for service. What was the average price per person, EXCLUDING the gratuity?

A. 11.73
B. 12
C. 13.8
D. 14
E. 15.87

How come the answer is B?

This is how I solved it and got A, which is incorrect.

$207 includes 15% gratuity so 0.15 * 207 = 31.05 Price EXCLUDING gratuity = 207 - 31.05 = 175.95 Average price per person = 175.95/15 = 11.73 Hello here is my approach so let x be the sum of the 15 lunch WITHOUT the 15 % 1.15 X = 207 X = 207/ 1.15 X= 180 so 180 is for 15 people the average price be 180 /15= 12 HENCE B HOPE THIS HELP BEST REGARDS Kudos [?]: 39 [0], given: 12 Intern Joined: 19 Dec 2011 Posts: 19 Kudos [?]: 10 [1], given: 37 The price of lunch for 15 people was$207.00, including a [#permalink]

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25 Aug 2012, 11:33
1
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check the option :

12

12 * 15 = 180

180 + [ 18 + 9 ] ( 15 % of 180) = 207

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27 Feb 2013, 20:31
Can someone please explain how you compute 207/1.15 under two minutes quickly? I think my division need help
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07 May 2014, 14:06
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For those who are intimidated by the division I found back solving to be very efficient for this problem.

I started with D $14.00 14*15 = 210 210>207 and that doesn't even have the gratuity added. So I know right there that D and E are out and a 20 cent deduction on choice C is probably still going to be too high. Went to answer choice B.$12.00

12*15=180 15% of 180=27 180+72=207.00

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12 Sep 2014, 05:42
enigma123 wrote:
The price of lunch for 15 people was $207.00, including a 15 percent gratuity for service. What was the average price per person, EXCLUDING the gratuity? (A)$11.73
(B) $12.00 (C)$13.80
(D) $14.00 (E)$15.87

[Reveal] Spoiler:
How come the answer is B?

This is how I solved it and got A, which is incorrect.

$207 includes 15% gratuity so 0.15 * 207 = 31.05 Price EXCLUDING gratuity = 207 - 31.05 = 175.95 Average price per person = 175.95/15 = 11.73 let x be the total without gratuity.. then we shall form x+0.15x = 207 1.15x=207 x=207/1.15 x=180. x/15 for each person then 180/15 = 12.. Kudos [?]: 33 [0], given: 81 SVP Status: The Best Or Nothing Joined: 27 Dec 2012 Posts: 1844 Kudos [?]: 2861 [0], given: 193 Location: India Concentration: General Management, Technology WE: Information Technology (Computer Software) The price of lunch for 15 people was$207.00, including a 15 [#permalink]

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30 Oct 2014, 23:34
Per head without gratuity $$= \frac{207 * 100}{115 * 15} = \frac{900}{75} = 12$$

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Re: The price of lunch for 15 people was $207.00, including a 15 [#permalink] Show Tags 07 Jan 2015, 12:19 The price included a gratuity of 15% on top of the original bill, hence$207.00 represents 115% of bill $x.yz$207.00 ------- 115%
$x.yz ---------- 100% x =$180.00

Bill per person: $180.00 : 15 =$12.00

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Re: The price of lunch for 15 people was $207.00, including a 15 [#permalink] Show Tags 03 May 2016, 10:38 1 This post received KUDOS Expert's post enigma123 wrote: The price of lunch for 15 people was$207.00, including a 15 percent gratuity for service. What was the average price per person, EXCLUDING the gratuity?

(A) $11.73 (B)$12.00
(C) $13.80 (D)$14.00
(E) $15.87 [Reveal] Spoiler: How come the answer is B? This is how I solved it and got A, which is incorrect.$207 includes 15% gratuity so 0.15 * 207 = 31.05

Price EXCLUDING gratuity = 207 - 31.05 = 175.95

Average price per person = 175.95/15 = 11.73

Solution:

An easy way to solve this problem is to translate what is provided in the question into a mathematical equation. We know that the total bill for 15 people was 207 dollars, including the 15 percent gratuity. We use the value 1.15 in the equation below to account for the meal itself plus the gratuity. We can use x as the average cost per person for the meal without the gratuity. Thus, we can say:

(1.15)(15)(x) = 207

(115/100)(15)(x) = 207

(115)(15)(x) = (207)(100)

We can divide the entire equation by 3. Doing so gives us:

(115)(5)(x) = (69)(100)

We can divide the entire equation by 5 and we get:

(115)x = (69)(20)

We can again divide the entire equation by 5 and we get:

(23)x = (69)(4)

We can again divide the entire equation by 23 and we get:

x = (3)(4)

x = 12

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07 May 2016, 07:07
enigma123 wrote:
The price of lunch for 15 people was $207.00, including a 15 percent gratuity for service. What was the average price per person, EXCLUDING the gratuity? (A)$11.73
(B) $12.00 (C)$13.80
(D) $14.00 (E)$15.87

[Reveal] Spoiler:
How come the answer is B?

This is how I solved it and got A, which is incorrect.

$207 includes 15% gratuity so 0.15 * 207 = 31.05 Price EXCLUDING gratuity = 207 - 31.05 = 175.95 Average price per person = 175.95/15 = 11.73 let x be the avg price per person excluding gratuity then 15x+ 15/100(15x)=207 by solving x =12 answer B Kudos [?]: 38 [0], given: 7 Board of Directors Status: QA & VA Forum Moderator Joined: 11 Jun 2011 Posts: 3240 Kudos [?]: 1177 [0], given: 327 Location: India GPA: 3.5 WE: Business Development (Commercial Banking) Re: The price of lunch for 15 people was$207.00, including a 15 [#permalink]

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07 May 2016, 09:35
enigma123 wrote:
The price of lunch for 15 people was $207.00, including a 15 percent gratuity for service. What was the average price per person, EXCLUDING the gratuity? (A)$11.73
(B) $12.00 (C)$13.80
(D) $14.00 (E)$15.87

[Reveal] Spoiler:
How come the answer is B?

This is how I solved it and got A, which is incorrect.

$207 includes 15% gratuity so 0.15 * 207 = 31.05 Price EXCLUDING gratuity = 207 - 31.05 = 175.95 Average price per person = 175.95/15 = 11.73 Quote:$207.00, including a 15 percent gratuity for service.

That means 115% = 207

So, 100% = $$\frac{207}{115}*100$$ => 180

Further it is given -

Quote:
price of lunch for 15 people was $207.00, including a 15 percent gratuity for service. So, Price of lunch for 15 people excluding 15 percent gratuity for service = $$180$$ Or, Price of lunch for 15 people excluding 15 percent gratuity for service = $$\frac{180}{15}$$ => $$12$$ Hence average price excluding gratuity for service is 12 _________________ Thanks and Regards Abhishek.... PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only ) Kudos [?]: 1177 [0], given: 327 Re: The price of lunch for 15 people was$207.00, including a 15   [#permalink] 07 May 2016, 09:35

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