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

 It is currently 20 Jul 2018, 15:33

### 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

### Show Tags

02 May 2012, 15:55
7
32
00:00

Difficulty:

55% (hard)

Question Stats:

64% (01:33) correct 36% (01:35) wrong based on 1893 sessions

### HideShow timer Statistics

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

How come the answer is B?

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

### Show Tags

28 Feb 2013, 01:50
9
6
DelSingh wrote:
Can someone please explain how you compute 207/1.15 under two minutes quickly? I think my division need help

Transform decimal into fraction: $$1.15=1\frac{15}{100}=1\frac{3}{20}=\frac{23}{20}$$.

$$Bill*1.15=207$$ --> $$Bill*\frac{23}{20}=207$$ --> $$Bill*\frac{23}{20}=9*23$$ --> $$\frac{Bill}{20}=9$$ --> $$Bill=180$$.

Hope it helps.
_________________
Intern
Joined: 13 Nov 2010
Posts: 40
Re: The price of lunch for 15 people was $207 including a 15% [#permalink] ### Show Tags 03 May 2012, 07:51 3 3 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. ##### General Discussion VP Status: Top MBA Admissions Consultant Joined: 24 Jul 2011 Posts: 1454 GMAT 1: 780 Q51 V48 GRE 1: Q800 V740 Re: Price of lunch [#permalink] ### Show Tags 02 May 2012, 21:23 1 1 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) _________________ GyanOne | Top MBA Rankings and MBA Admissions Blog Top MBA Admissions Consulting | Top MiM Admissions Consulting Premium MBA Essay Review|Best MBA Interview Preparation|Exclusive GMAT coaching Get a FREE Detailed MBA Profile Evaluation | Call us now +91 98998 31738 Manager Joined: 02 Jun 2011 Posts: 133 Re: Price of lunch [#permalink] ### Show Tags 03 May 2012, 02:48 1 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 ? Math Expert Joined: 02 Sep 2009 Posts: 47157 Re: Price of lunch [#permalink] ### Show Tags 03 May 2012, 12:56 8 1 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.

_________________
Manager
Joined: 17 Sep 2011
Posts: 163

### Show Tags

14 May 2012, 06:10
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
Intern
Joined: 19 Dec 2011
Posts: 19

### Show Tags

20 Feb 2013, 14:14
1
let the price before gratuity = x
that means that (115/100)x = 207

Solving for x we get 180. 180/15 = 12. Answer B.
Manager
Joined: 25 Jul 2012
Posts: 70
Location: United States

### Show Tags

07 May 2014, 15:06
1
1
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
Intern
Joined: 25 Jul 2014
Posts: 18
Concentration: Finance, General Management
GPA: 3.54
WE: Asset Management (Venture Capital)

### Show Tags

12 Sep 2014, 06:42
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

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.. SVP Status: The Best Or Nothing Joined: 27 Dec 2012 Posts: 1837 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]

### Show Tags

31 Oct 2014, 00:34
Per head without gratuity $$= \frac{207 * 100}{115 * 15} = \frac{900}{75} = 12$$

_________________

Kindly press "+1 Kudos" to appreciate

Current Student
Status: Eagles Become Vultures
Joined: 19 Jun 2014
Posts: 61
Concentration: Finance, Strategy
Schools: LBS '18 (M)
GMAT 1: 710 Q48 V39
GPA: 4
WE: Corporate Finance (Energy and Utilities)
Re: The price of lunch for 15 people was $207.00, including a 15 [#permalink] ### Show Tags 07 Jan 2015, 13:19 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
Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 2973
Location: United States (CA)
Re: The price of lunch for 15 people was $207.00, including a 15 [#permalink] ### Show Tags 03 May 2016, 11:38 1 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 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

_________________

Scott Woodbury-Stewart
Founder and CEO

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

Current Student
Joined: 23 Mar 2016
Posts: 33
Schools: Tulane '18 (M)

### Show Tags

07 May 2016, 08:07
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

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 Board of Directors Status: QA & VA Forum Moderator Joined: 11 Jun 2011 Posts: 3653 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]

### Show Tags

07 May 2016, 10:35
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

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 ) Re: The price of lunch for 15 people was$207.00, including a 15 &nbs [#permalink] 07 May 2016, 10:35

Go to page    1   2    Next  [ 32 posts ]

Display posts from previous: Sort by

# Events & Promotions

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.