A computer store originally bought 1,000 modems at a total cost of d d

Question

A computer store originally bought 1,000 modems at a total cost of d dollars. If each modem was sold for 25 percent more than its original cost, what was the individual price, in terms of d, of each modem sold?

(A) d/800
(B) 5d/1000
(C) 125d
(D) d/1000 + 25
(E) 125/(1000d)

Kudos for a correct solution.

(A) d/800 
(B) 5d/1000 
(C) 125d 
(D) d/1000 + 25 
(E) 125/(1000d)

chetan2u · Answer

A... each modem *1.25=(d/1000)*1.25
 =d/800

vedavyas9 · Answer

I'm getting d/1250

1.25* original price = d/1000

what am i considering wrong

EMPOWERgmatRichC · Answer

Hi vedavyas9,

Since you're choosing to approach this algebraically, I'm going to add some labeling to your work....

1,000 purchased for a total of D dollars.....

Each modem costs D/1,000 dollars....

Each modem is then sold for 25% ABOVE the cost:

(1.25)(D/1,000) = 1.25D/1,000

1.25D/1,000 = 125D/100,000

125/1,000 = 1/8 so....
125/100,000 = 1/800

So the sell price of each modem is D/800

Final Answer:  A

GMAT assassins aren't born, they're made,
Rich

vedavyas9 · Answer

EMPOWERgmatRichC  - Thanks mate.
I got confused and thought that laptops are bought at 1.25 times the original price.
But when i saw ur ans i understood that they are bought for d/1000 and sold again at 1.25 times original price.

82vkgmat · Answer

Cost of each model = d/1000
So selling price = 25% more = 1.25*d/1000 = d/800.

Answer A.

EMPOWERgmatRichC · Answer

Hi vedavyas9,

Most Test Takers make plenty of little mistakes during their studies - don't be afraid of that, but DO work to correct it. So much of your performance on Test Day will just come down to the amount of work that you're willing to put in. By work, I don't mean "rub your chin and do work 'in your head'" - I mean take notes, label your work, do what is necessary to confirm that you have the correct answer. You'll come to find that most of the work is actually pretty easy (because it IS), so the GMAT really isn't an IQ test or a "math" test or a "vocabulary" test - it's a test of lots of skills that Business Schools think are important. Don't skimp on the notes, EVER. If you can promise me that you won't make any silly mistakes on Test Day, then I'll promise you that you'll earn a score that will make every Business School happy.

GMAT assassins aren't born, they're made,
Rich

PareshGmat · Answer

Quantity ...................... Each Cost ............ Total

1000 .................................  \frac{d}{1000}  ............ d

Adding 25% to  \frac{d}{1000}

= \frac{d}{1000} * \frac{125}{100} = \frac{d}{800}

Answer = A

BrentGMATPrepNow · Answer

Given: d = total cost of 1000 modems 
So, d/1000 = cost of ONE modem

After the 25% increase, the retail price per modem = (d/1000) + 25% of (d/1000)
= (d/1000) + 0.25 (d/1000) 
= d/1000 + 0.25d/1000 
= 1.25d/1000
Check answer choices . . . . not there!
We need to find an equivalent form of 1.25d/1000 that's among the answer choices.

Take: 1.25d/1000
Divide top and bottom by 1.25 to get: d/800

Answer: A

Cheers, 
Brent

ScottTargetTestPrep · Answer

The selling price for each modem is:

d/1000 * 5/4 = 5d/4000 = d/800

Answer: A

mailson · Answer

I prefer to work with fractions rather than with some percents:

Individual cost = d * 1/1000 * 5/4

Individual cost = d * 1/200 * 1/4

Individual cost = d/800

bumpbot · Answer

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A computer store originally bought 1,000 modems at a total cost of d d

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