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21 Apr 2012, 21:18
3
13
00:00

Difficulty:

65% (hard)

Question Stats:

66% (03:07) correct 34% (03:19) wrong based on 322 sessions

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21 Apr 2012, 23:03
5
4
boomtangboy wrote:

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04 Oct 2013, 13:21
2
1
1st Try selecting options which are divisible by 300
If you select 30 as x.Therefore avg cost of each calculator 300/30 i.e 10$. Set aside 2 .So we have 28 calc. Each calc sold at 5$ more i.e 10+5=15$& 15x28=$420
Difference is $420-$300=120
E) is the answer hope it helps
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Joined: 06 Sep 2013
Posts: 1569
Concentration: Finance
Re: A merchant paid $300 for a shipment of x identical calculators. The [#permalink] ### Show Tags 11 Jan 2014, 08:52 boomtangboy wrote: A merchant paid$300 for a shipment of x identical calculators. The merchant used 2 of the calculators as demonstrators and sold each of the others for $5 more than the average (arithmetic mean) cost of the x calculators. If the total revenue from the sale of the calculators was$120 more than the cost of the shipment, how many calculators were in the shipment?

A. 24
B. 25
C. 26
D. 28
E. 30

Is this question correct? Shipping cost given but cost of each calculator missing.....

I'd go with backsolving on this one though I must admit that originally I tried to solve algebraically and was stuck with variables and quadratics

We will have (300/x + 5)(x-2) = 420

Then begin replacing, I started with 25 cause 26 would not yield an integer when divided by 300 but it didn't work, so I realized I needed a bigger number and the only factor of 30 that could work was E

So E

Hope it helps
Cheers!
J
Manager
Joined: 20 Dec 2013
Posts: 224
Location: India

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20 Mar 2014, 19:56
2

Total Calculators = x

Cost per calculator = $$\frac{300}{x}$$

Calculators sold = x-2

Selling price per calculator = $$\frac{300}{x} +5$$

Total amount received = $$(\frac{300}{x} + 5) * (x-2) = 420$$

Solving,

$$x^2 - 26x - 120 = 0$$

x = 30
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Re: A merchant paid $300 for a shipment of x identical calculators. The [#permalink] ### Show Tags 06 Dec 2017, 14:25 2 Hi All, The information in the prompt include a variety of nice 'round' numbers, so it's likely that the number of calculators in the shipment is also a round number AND divides evenly into 300. Only two of the answers 'fit' that idea - 25 and 30, so let's TEST THE ANSWERS and see if either of those values fits all of the information given in the prompt. IF.... X = 30 and there are 30 calculators in the shipment.... The merchant paid$300/30 = $10 per calculator 2 calculators were used for demonstrations, so 30 - 2 = 28 calculators were sold Each of the 'sold' calculators brought in$10+$5 =$15
The total revenue was ($15)(28) =$420
The total profit was $420 -$300 = $120 This is an exact match for what we were told, so this MUST be the answer. Final Answer: GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at: Rich.C@empowergmat.com The Course Used By GMAT Club Moderators To Earn 750+ souvik101990 Score: 760 Q50 V42 ★★★★★ ENGRTOMBA2018 Score: 750 Q49 V44 ★★★★★ Intern Joined: 08 Dec 2017 Posts: 15 Re: A merchant paid$300 for a shipment of x identical calculators. The  [#permalink]

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27 Dec 2017, 16:36
5 is gained every calculator sold. Also, if 300 calculators cost x dollars, then 2 cost 600/x.

5(x-2) -600/x=120

(X-2)-120/x=24
X^2-2x-120=24x
x^2-26x-120=0

x^2=26x+120

X=13+- sqroot(169+120)

X=13+-17

x= 30

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Joined: 01 May 2017
Posts: 82
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21 Sep 2019, 06:09
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