Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 43792

Question Stats:
77% (01:49) correct 23% (02:39) wrong based on 100 sessions
HideShow timer Statistics



Math Expert
Joined: 02 Sep 2009
Posts: 43792

Re M1534 [#permalink]
Show Tags
15 Sep 2014, 23:57
1
This post received KUDOS
Expert's post
1
This post was BOOKMARKED
Official Solution:In the month of November, a company sold 3000 items of model A and 1000 items of model B. Items of model A accounted for 60% of the company's monthly sales in dollars while items of model B accounted for 40% of the monthly sales in dollars. If the company had sold 1000 items of model A less than it actually did, what percent of the total monthly sales in dollars would have been attributed to model A?A. 48 B. 50 C. 52 D. 54 E. 55 Let \(S\) denote the total November sales of the company. The price of an item of model A = \(0.6*\frac{S}{3000}\); the price of an item of model B = \(0.4*\frac{S}{1000}\). If the company had sold 2000 items of model A, the revenue from sales of model A would have amounted to \(0.6*\frac{S}{3000}*2000 = 0.6S*\frac{2}{3} = 0.4S\) which is equal to the revenue from sales of model B. So, in the hypothetical case described in the stem, the two models would have accounted for 50% of the monthly sales each. Alternative explanation  picking numbers Let the total revenue be \($10,000\); then revenue from Model A is \($6,000\) for 3,000 units or \($2\) per unit and Model B's revenue is \($4,000\) for 1,000 units or \($4\) per unit. If we had sold only 2,000 units of model A, the total revenue would have been \($2*2,000 +$4*1,000 =$8,000\). At this point it is clear that model A and B bring equal amounts of revenue (\($4,000\) each) and half of monthly sales are attributed to model A. Answer: B
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Manager
Joined: 14 Jul 2014
Posts: 96

Re: M1534 [#permalink]
Show Tags
14 Jan 2015, 05:28
2
This post received KUDOS
A = Qty * Price = 3000 a B = 1000 * b = 1000 b
Now for A, 3000 a / (3000 a + 1000 b) = 3a / ( 3a + b) = 6 / 10 ……. ( i )  As given in the statement
Similarly , b / (3a + b) = 4 / 10 ……….. ( ii )
DIVIDE i / ii = 3a / b = 3 / 2 which gives us b = 2a
NOW As asked in the problem, find 2a / ( 2a + b)
Subtitute b , we get = 2a / 4a = 50%



Verbal Forum Moderator
Joined: 15 Apr 2013
Posts: 195
Location: India
Concentration: General Management, Marketing
GMAT Date: 11232015
GPA: 3.6
WE: Science (Other)

Re: M1534 [#permalink]
Show Tags
11 Jul 2015, 05:05
Dear Bunuel, Could you please confirm that approach used by buddyisraelgmat is correct. I also used the same approach. Regards Vikas



Math Expert
Joined: 02 Sep 2009
Posts: 43792

Re: M1534 [#permalink]
Show Tags
11 Jul 2015, 07:46



Director
Joined: 10 Mar 2013
Posts: 584
Location: Germany
Concentration: Finance, Entrepreneurship
GPA: 3.88
WE: Information Technology (Consulting)

Re: M1534 [#permalink]
Show Tags
14 Oct 2015, 13:37
Bunuel wrote: In the month of November, a company sold 3000 items of model A and 1000 items of model B. Items of model A accounted for 60% of the company's monthly sales while items of model B accounted for 40% of the monthly sales. If the company had sold 1000 items of model A less than it actually did, what percent of the total monthly sales would have been attributed to model A?
A. 48 B. 50 C. 52 D. 54 E. 55 Here's one more approach: 60%=20%+20%+20%, 40%=20%+20% > 3000/3=1000=20%, 1000/2=500=20% ==> 1000a=500b means b=2a 2000a/2000a+2000a (=1000b) = 50%
_________________
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



Intern
Joined: 20 Mar 2013
Posts: 1
WE: Design (Energy and Utilities)

Re: M1534 [#permalink]
Show Tags
11 Dec 2015, 03:27
1
This post received KUDOS
the question never specifies that monthly sales are in dollars...where as monthly sales can be numbers also... what if 60% of A is 3000 units.. so monthly sales is 5000 units..



Intern
Joined: 23 Apr 2016
Posts: 22
Location: Finland
Concentration: General Management, International Business
GPA: 3.65

Re: M1534 [#permalink]
Show Tags
19 Oct 2016, 11:11
1
This post received KUDOS
I agree with vijayjec02, the question stem was a bit confusing. I had to assume that may be question intends to mean this. Question asked "A company sold 3000 items of model A and 1000 items of model B" and then says "Items of model A accounted for 60% of the company's monthly sales." Item of model A did not amount for 60% of sales... items amount for 75% of total sales. Money generated from the sale of item A amounted for 60%... Otherwise I think it is a nice question.



Intern
Joined: 07 Mar 2017
Posts: 1

Re: M1534 [#permalink]
Show Tags
09 Mar 2017, 03:56
Lets say total sales = 100, so for 1000 items of A sales = 20 A: 20 + 20 +20 =60 B: 40
When sales of A is reduced by 1000, total sales = remaining 2000 = 40 There is no change in B sales. Total sale : = 40+40=80
So %age of sale A: = 40/80* 100 = 50%



Intern
Joined: 22 Aug 2017
Posts: 2

Re: M1534 [#permalink]
Show Tags
10 Sep 2017, 04:14
1
This post received KUDOS
The question stem is not clear in this case because monthly sales can be in terms of both money and quantity. Bunuel, I request you to replace this question stem to avoid any ambiguity in the meaning of the stem.



Manager
Joined: 22 Apr 2017
Posts: 110
Location: India
GPA: 3.7

Re: M1534 [#permalink]
Show Tags
08 Nov 2017, 01:00
1
This post received KUDOS
Scpkulkarni wrote: The question stem is not clear in this case because monthly sales can be in terms of both money and quantity. Bunuel, I request you to replace this question stem to avoid any ambiguity in the meaning of the stem. I too agree. The question stem never specifies the sales in terms of revenue or number of items.



Math Expert
Joined: 02 Sep 2009
Posts: 43792

Re: M1534 [#permalink]
Show Tags
08 Nov 2017, 22:26



Senior Manager
Joined: 02 Jul 2017
Posts: 288

1
This post received KUDOS
Let price of item A = a And price of item B = b
A sold 3000 items => total sale/revenue = 3000a B sold 1000 items => total sale/revenue = 1000b
Total sales/revenue = 3000a + 1000b
A revenue accounted for 60% of total revenue => 60% of total = A's revenue =>\(\frac{60}{100}(3000a+1000b) = 3000a\) => 9000a +3000b =15000a => 2a = b
Now A sold 1000 less items = 2000 items => revenue = 2000a Total revenue = 2000a+1000b = 2000a + 1000*2a = 4000a <= as 2a =b
so % of revenue from A = \(\frac{Revenue of A}{Total revenue} * 100\)
= \(\frac{2000a}{4000a}*100\)
= 50%
Answer: B
Here is Bunuel 's solution ( in detail)
Let total sales/revenue from A and B = S
as revenue of A = 60% of S = 0.6*S = items sold by A * price of item A => 0.6*S = 3000 * price of item A
=>price of item A = \(0.6 * \frac{S}{3000}\)
same way : as revenue of B = 40% of S = 0.4*S = items sold by B * price of item B => 0.4*S = 1000 * price of item B
=>price of item B = \(0.4 * \frac{S}{1000}\)
Now as A sold 1000 less items => items sold = 2000
So revenue from A = price of item A * number of items sold = \(0.6 * \frac{S}{3000} * 2000\) = 0.4*S
That is, revenue from A = 0.4*S and revenue from B = 0.4*S
so % of revenue from A = \(\frac{Revenue of A}{Total revenue} * 100\)
= \(\frac{0.4*S}{0.4*S + 0.4*S}*100\)
= 50%



Intern
Joined: 12 Dec 2017
Posts: 8

Re: M1534 [#permalink]
Show Tags
30 Dec 2017, 03:43
I feel this question is again a 500level question. GMAT Quant has been steadily becoming more challenging and I feel such level questions can no more be incorrectly tagged 600 level.










