BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Ted's electronics

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
GMAT Instructor
Posts: 1578
Joined: Thu May 28, 2009 8:02 am
Thanked: 128 times
Followed by:34 members
GMAT Score:760

Ted's electronics

by Osirus@VeritasPrep » Fri May 28, 2010 7:36 am
Ted owns an electronics business and is calculating the price of a certain group of microwaves in the inventory he purchased. If the total price of m equally priced microwaves was $18,000, what was the price per microwave in the inventory?

(1) If the price per microwave in Ted's inventory had been $10 more, the total price of the m microwaves would have been $5,000 more.

(2) If the price per microwave in Ted's inventory had been $9 less, the total price of the m microwaves would have been 25 percent less

OA [spoiler]D I'm not so much interested in the answer, could someone show me how to set up the equations for each statement and solve it all the way through? I set up statement one like this

18,000/m = 23,000. Why is that incorrect? Help me to translate the word problem if you can. Thanks in advance.[/spoiler]
https://www.beatthegmat.com/the-retake-o ... 51414.html

Brandon Dorsey
GMAT Instructor
Veritas Prep

Buy any Veritas Prep book(s) and receive access to 5 Practice Cats for free! Learn More.
Top
Source: — Data Sufficiency |
User avatar
GMAT Instructor
Posts: 147
Joined: Tue Aug 25, 2009 7:57 pm
Location: New York City
Thanked: 76 times
Followed by:17 members
GMAT Score:770

by Rich@VeritasPrep » Fri May 28, 2010 7:55 am
If we assign the variable p to the price per microwave, then the prompt basically boils down to:

pm = 18000. p = ?

This is because (price per microwave)*(number of microwaves) yields total cost. So if we know what m is, we can definitely find p.

Statement (1) actually looks like this:

(p + 10)*m = 18000+5000

This is because the price per microwave is now $10 greater, and we multiply that by m to get the new total of 23000.

(p + 10)*m = 18000+5000

pm + 10m = 23000 (by distribution)

18000 + 10m = 23000 (substitute 18000 for pm)

You now have one linear equation and one variable. You can definitely find m, and thus find p. SUFFICIENT


Statement (2) looks like this:

(p - 9)*m = .75*(18000)

Don't even worry about the right side of the equation:

pm - 9m = .75*(18000)

18000 - 9m = .75*(18000)

Again, one linear equation and one variable. You can find m, and thus find p. SUFFICIENT
Last edited by Rich@VeritasPrep on Fri May 28, 2010 8:29 am, edited 1 time in total.
Rich Zwelling
GMAT Instructor, Veritas Prep
Top
GMAT Instructor
Posts: 1578
Joined: Thu May 28, 2009 8:02 am
Thanked: 128 times
Followed by:34 members
GMAT Score:760

by Osirus@VeritasPrep » Fri May 28, 2010 8:04 am
Thanks for the response. One more question. Why can't we sub in 18,000/m for p? Shouldn't they be functionally the same?
https://www.beatthegmat.com/the-retake-o ... 51414.html

Brandon Dorsey
GMAT Instructor
Veritas Prep

Buy any Veritas Prep book(s) and receive access to 5 Practice Cats for free! Learn More.
Top
User avatar
GMAT Instructor
Posts: 147
Joined: Tue Aug 25, 2009 7:57 pm
Location: New York City
Thanked: 76 times
Followed by:17 members
GMAT Score:770

by Rich@VeritasPrep » Fri May 28, 2010 8:33 am
18000/m does indeed equal p ... but remember, p is the CURRENT price per unit, the price for which you're trying to find the value.

Each of the statements involves a NEW price per unit, a theoretical price per unit. Therefore, each of these hypothetical prices per unit is a value different from p.

I think you might have applied the formula forgetting to take into account that you can't use the variable p twice, if two different quantities are involved.

However, if you used p1 and p2, that might work ... but that's more work than you need to do for this problem :)

Make sense? Let me know if I can help anymore.
Rich Zwelling
GMAT Instructor, Veritas Prep
Top
GMAT Instructor
Posts: 1578
Joined: Thu May 28, 2009 8:02 am
Thanked: 128 times
Followed by:34 members
GMAT Score:760

by Osirus@VeritasPrep » Fri May 28, 2010 8:35 am
Thanks that helps tremendously.
https://www.beatthegmat.com/the-retake-o ... 51414.html

Brandon Dorsey
GMAT Instructor
Veritas Prep

Buy any Veritas Prep book(s) and receive access to 5 Practice Cats for free! Learn More.
Top
Newbie | Next Rank: 10 Posts
Posts: 4
Joined: Wed Sep 14, 2011 4:13 am

by puneetgangrade » Mon Nov 10, 2014 4:40 am
My doubt is driven by the explanation of this question in Veritas Data Sufficiency book, Q#72.

According to the book - "Though we get the value of P and M using the statement(1) and question stem, and when we start examining the statement(2), and reach to a one variable linear equation, why is it said that we need not further find the value of the variable ?"

In statement(2), what if the value of the variable after solving turns out to be different from the one found using statement(1) ?

Won't that contradict the answer ?
Top
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Mon Nov 10, 2014 4:52 am
Ted owns an electronics business and is calculating the price of a certain group of microwaves in the inventory he purchased. If the total price of m equally priced microwaves was $18,000, what was the price per microwave in the inventory?

(1) If the price per microwave in Ted's inventory had been $10 more, the total price of the m microwaves would have been $5,000 more.

(2) If the price per microwave in Ted's inventory had been $9 less, the total price of the m microwaves would have been 25 percent less
Price per microwave = (total price)/(number of microwaves) = 18000/m.

Question stem, rephrased:
What is the value of m?

Statement 1:
m = (total price increase)/(price increase per microwave) = 5000/10 = 500.
SUFFICIENT.

Statement 2:
Total price decrease = 25% of 18,000 = 4500.
m = (total price decrease)/(price decrease per microwave) = 4500/9 = 500.
SUFFICIENT.

The correct answer is D.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Post new topic Post Reply
• Page 1 of 1