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

 It is currently 14 Oct 2019, 09:53 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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.  In a small snack shop, the average (arithmetic mean) revenue

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

Hide Tags

Manager  Joined: 22 Sep 2010
Posts: 71
In a small snack shop, the average (arithmetic mean) revenue  [#permalink]

Show Tags

2
14 00:00

Difficulty:   5% (low)

Question Stats: 91% (01:23) correct 9% (01:42) wrong based on 1636 sessions

HideShow timer Statistics

In a small snack shop, the average (arithmetic mean) revenue was $400 per day over a 10-day period. During this period, if the average daily revenue was$360 for the first 6 days, what was the average daily revenue for the last 4 days?

A. $420 B.$440
C. $450 D.$460
E. $480 Originally posted by pzazz12 on 22 Oct 2010, 05:49. Last edited by Bunuel on 09 Oct 2012, 03:55, edited 1 time in total. Edited the question. Most Helpful Community Reply Intern  Joined: 17 Aug 2010 Posts: 48 Re: In a small snack shop......... [#permalink] Show Tags 5 pzazz12 wrote: In a small snack shop, the average (arithmetic mean) revenue was$400 per day over a 10-day period. During this period, if the average daily revenue was $360 for the first 6 days, what was the average daily revenue for the last 4 days? A.$420
B. $440 C.$450
D. $460 E.$480

D. $460 is my answer. 400 = x/10 x = 4000 For first 6 days = 360 * 6 =$2160

therefore for the last 4 days revenue is $4000 -$2160 = 3840
hence, airthmatic mean = 3840/4 = $460 Please let me know the OA. Also, I am very bad in explaining things. I am waiting for Bunuel to respond. He is extremly good in explaining solution. _________________ I don't want kudos.. I want to see smile on your face if I am able to help you.. which is priceless. General Discussion Math Expert V Joined: 02 Sep 2009 Posts: 58320 Re: In a small snack shop......... [#permalink] Show Tags 3 1 pzazz12 wrote: In a small snack shop, the average (arithmetic mean) revenue was$400 per day over a 10-day period. During this period, if the average daily revenue was $360 for the first 6 days, what was the average daily revenue for the last 4 days? A.$420
B. $440 C.$450
D. $460 E.$480

The average revenue was $400 per day over a 10-day period --> total revenue over 10-day period is 10*$400=$4,000; The average daily revenue was$360 for the first 6 days --> total revenue for the first 6 days is 6*$360=2,160; Total revenue for the last 4 days is$4,000-2,160=$1,840; Average daily revenue for the last 4 days is$1,840/4=$460. Answer: D. _________________ Intern  Joined: 17 Aug 2010 Posts: 48 Re: In a small snack shop......... [#permalink] Show Tags 1 Like I said, what Bunuel says is OA for me. _________________ I don't want kudos.. I want to see smile on your face if I am able to help you.. which is priceless. Intern  Joined: 01 Oct 2010 Posts: 1 Re: In a small snack shop......... [#permalink] Show Tags 1 I solved it in another way, but not sure whether its correct. Can some one help me by validating.. Let 'x' be the average daily revenue for last 4 days. [6(360)+4(x)]/10 = 400 solving, x = 460 Thanks in advance Intern  Joined: 15 Apr 2010 Posts: 38 Re: In a small snack shop......... [#permalink] Show Tags 3 weighted average total 10 days, avg10 of this period is 400 first 6 days avg6 is 360 which is deltaAvg6 = 40 away from the overall avg10 last 4 day avg4 must have more weight to pull the avg10 to 400 (if 5 days-5 days then last 5 must have 440 so that avg10 is pulled back to 400, but this is 6/4, so we know last 4 days avg must have much more weight, so avg4 > 440, eliminate few choices) since ratio of weight of 2 periods is 6/4 = 3/2, the avg4 must compensate for the loss of deltaAvg6 a 3/2 amount of deltaAvg6 so that the avg10 is pulled back to 400. therefore the last 4 days must have deltaAvg4 = 3/2 * deltaAvg6 = 3/2 * 40 = 60. so avg4 = 400 + deltaAvg4 = 400 + 60 = 460 --> D Director  Status: My Thread Master Bschool Threads-->Krannert(Purdue),WP Carey(Arizona),Foster(Uwashngton) Joined: 28 Jun 2011 Posts: 809 Re: In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags 460 400 x 10= 4000 360 x 6 = 2160 4000-2160 = 1840/4=460 Manager  B Joined: 13 Feb 2012 Posts: 129 Location: Italy Concentration: General Management, Entrepreneurship GMAT 1: 560 Q36 V34 GPA: 3.1 WE: Sales (Transportation) Re: In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags Bunuel's way of solving is definitely the most straight forward one; thanks! _________________ "The Burnout" - My Debrief Kudos if I helped you Andy Intern  Joined: 24 Apr 2012 Posts: 45 Re: In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags Ans: the total revenue for 10 days is 10x400=4000 and the total revenue for first 6 days is 6x360=2160, so the average for last 4 days will be (4000-2160)/4 = 460 (D). _________________ www.mnemoniceducation.com TURN ON YOUR MINDS!!! Senior Manager  Joined: 23 Oct 2010 Posts: 324 Location: Azerbaijan Concentration: Finance Schools: HEC '15 (A) GMAT 1: 690 Q47 V38 Re: In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags (400-360)*6/4=60 400+60=460 _________________ Happy are those who dream dreams and are ready to pay the price to make them come true I am still on all gmat forums. msg me if you want to ask me smth Senior Manager  B Joined: 10 Mar 2013 Posts: 467 Location: Germany Concentration: Finance, Entrepreneurship Schools: WHU MBA"20 (A) GMAT 1: 580 Q46 V24 GPA: 3.88 WE: Information Technology (Consulting) In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags I've solved it using weighted average formula: So, 360 is 40 less then the average of 400 -> -40 * 6 Days; We have 4 Days and need to calculate the revenue =X 6*(-40) + 4*x=0 X=60, so it means that for the last 4 days the revenue was 60 above the average = 400+60 =460 (D) Time: < 1 minute _________________ When you’re up, your friends know who you are. When you’re down, you know who your friends are. Share some Kudos, if my posts help you. Thank you ! 800Score ONLY QUANT CAT1 51, CAT2 50, CAT3 50 GMAT PREP 670 MGMAT CAT 630 KAPLAN CAT 660 Manager  Joined: 26 Nov 2014 Posts: 84 In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags In a small snack shop, the average (arithmetic mean) revenue was$400 per day over a 10-day period. During this period, if the average daily revenue was $360 for the first 6 days, what was the average daily revenue for the last 4 days? Avg revenue per day = 400 Total revenue for 10 days = 4000 Avg Revenue for first 6 days = 360 Total revenue for first 6 days = 360 x 6 = 2160 Total revenue for 10 days = Total revenue for first 6 days + Total revenue for last 4 days 4000 = 2160 + X X=1840, which is Total revenue for last 4 days Avg revenue for last 4 days = $$\frac{1840}{4}$$ = 460. _________________ Consider Kudos for my post, if it is helpful. TIA Target Test Prep Representative D Status: Founder & CEO Affiliations: Target Test Prep Joined: 14 Oct 2015 Posts: 8041 Location: United States (CA) Re: In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags 2 pzazz12 wrote: In a small snack shop, the average (arithmetic mean) revenue was$400 per day over a 10-day period. During this period, if the average daily revenue was $360 for the first 6 days, what was the average daily revenue for the last 4 days? A.$420
B. $440 C.$450
D. $460 E.$480

This is a problem testing us on our knowledge of weighted averages. To solve, we can set up a weighted average equation:

(Revenue for first 6 days + Revenue for final 4 days)/10 days = 400

We know that the average revenue for the first 6 days was $360. We let r be the average daily revenue for the final four days, so we have (360 x 6 + 4r)/10 = 400 2,160 + 4r = 4,000 4r = 1,840 r = 460 Answer is D. _________________ Scott Woodbury-Stewart Founder and CEO Scott@TargetTestPrep.com See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews If you find one of my posts helpful, please take a moment to click on the "Kudos" button. CEO  V Joined: 12 Sep 2015 Posts: 3995 Location: Canada In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags 1 Top Contributor pzazz12 wrote: In a small snack shop, the average (arithmetic mean) revenue was$400 per day over a 10-day period. During this period, if the average daily revenue was $360 for the first 6 days, what was the average daily revenue for the last 4 days? A.$420
B. $440 C.$450
D. $460 E.$480

If the average (mean) daily revenue over 10 days is $400/day, then the TOTAL 10-DAY REVENUE = (10)($400) = $4000 The average daily revenue for the first 6 days is$360. So, the TOTAL 6-DAY REVENUE = (6)($360) =$2160

So, the TOTAL REVENUE for the last 4 days = $4000 -$2160 = $1840 So, the AVERAGE daily revenue for those 4 days =$1840/4 = $460 Answer: RELATED VIDEO _________________ Director  G Joined: 02 Sep 2016 Posts: 649 Re: In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags pzazz12 wrote: In a small snack shop, the average (arithmetic mean) revenue was$400 per day over a 10-day period. During this period, if the average daily revenue was $360 for the first 6 days, what was the average daily revenue for the last 4 days? A.$420
B. $440 C.$450
D. $460 E.$480

Total revenue for 10 days= 400*10= 4000
Total revenue for 6 days= 360*6= 2160

Thus the total revenue for remaining 4 days would be 4000-2160=1840

The average revenue for 4 days= 1840/4= 460
Manager  G
Joined: 09 Jan 2016
Posts: 102
GPA: 3.4
WE: General Management (Human Resources)
Re: In a small snack shop, the average (arithmetic mean) revenue  [#permalink]

Show Tags

pzazz12 wrote:
In a small snack shop, the average (arithmetic mean) revenue was $400 per day over a 10-day period. During this period, if the average daily revenue was$360 for the first 6 days, what was the average daily revenue for the last 4 days?

A. $420 B.$440
C. $450 D.$460
E. $480 Total revenue 400* 10 = 4000 first 6 days = 360 *6 = 2160 rest of the four days = 1840 4x = 1840 X= 360 Manager  G Joined: 07 Jun 2017 Posts: 162 Location: India Concentration: Technology, General Management GMAT 1: 660 Q46 V38 GPA: 3.6 WE: Information Technology (Computer Software) Re: In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags The below is another method(easier) 400-360 = 40 for 6 days 40*6 = 240 this 240 need to be divide by remaining 4 days = 60 60 need to added to the average = 400+60 = 460 answer 460 _________________ Regards, Naveen email: nkmungila@gmail.com Please press kudos if you like this post Intern  B Joined: 31 Oct 2016 Posts: 1 Re: In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags 360*6 +4x= 400*10 4x= 1840 x= 460 EMPOWERgmat Instructor V Status: GMAT Assassin/Co-Founder Affiliations: EMPOWERgmat Joined: 19 Dec 2014 Posts: 15240 Location: United States (CA) GMAT 1: 800 Q51 V49 GRE 1: Q170 V170 Re: In a small snack shop, the average (arithmetic mean) revenue [#permalink] Show Tags 1 1 Hi All, There are a number of ways to "do the math" on this type of question. Using the standard Average Formula will work perfectly here, and you'll be asked to use it a couple of times over the course of the Quant section, so you shouldn't try to avoid it. That having been said, there's a weighted average "pattern" that can be used against this question: The average of the 10 days =$400

The average for the first 6 days = $360. This means that - on each of the first 6 days - each day was$40 "behind" the average. To get the average "up" to $400, the remaining 4 days have to "make up" for that deficit… 6 x$40 = $240 "behind" The last 4 days have to be above 400 by an amount that will make up for the$240.

$240/4 =$60. This means that each of the last 4 days needs to be $460 for the overall average to be$400.

GMAT assassins aren't born, they're made,
Rich
_________________
Senior Manager  P
Joined: 10 Apr 2018
Posts: 266
Location: United States (NC)
Re: In a small snack shop, the average (arithmetic mean) revenue  [#permalink]

Show Tags

Hello,

To avoid calculations we can use deviation method

400=360+(4x/10)
4x= 400
x= 100
=360+100= 460
hence option D
_________________
Probus

~You Just Can't beat the person who never gives up~ Babe Ruth Re: In a small snack shop, the average (arithmetic mean) revenue   [#permalink] 17 Aug 2018, 12:30

Go to page    1   2    Next  [ 22 posts ]

Display posts from previous: Sort by

In a small snack shop, the average (arithmetic mean) revenue

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne  