batteries (OG)

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 28
Joined: Mon Aug 29, 2011 6:43 pm
Thanked: 1 times

batteries (OG)

by razorback » Mon Sep 19, 2011 5:20 pm
A dealer originally bought 100 identical batteries at a total cost of q dollars. If each battery was sold at 50 percent above the original cost per battery, then, in terms of q, for how many dollars was each battery sold?

(A) 3q/200 (read: 3q all over 200)
(B) 3q/2 (read: 3q all over 2)
(C) 150q
(D) q/100 + 50 (read q over 100, then add 50)
(E) 150/q

Official answer soon.

This question is #84/230 from the Official Guide, which I interpret as "slightly below average" difficulty. I have stared down the explanation in the book and still can't grasp how this problem should be worked out.

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pm
Location: Milpitas, CA
Thanked: 1854 times
Followed by:523 members
GMAT Score:770

by Anurag@Gurome » Mon Sep 19, 2011 7:02 pm
razorback wrote:A dealer originally bought 100 identical batteries at a total cost of q dollars. If each battery was sold at 50 percent above the original cost per battery, then, in terms of q, for how many dollars was each battery sold?

(A) 3q/200 (read: 3q all over 200)
(B) 3q/2 (read: 3q all over 2)
(C) 150q
(D) q/100 + 50 (read q over 100, then add 50)
(E) 150/q

Official answer soon.

This question is #84/230 from the Official Guide, which I interpret as "slightly below average" difficulty. I have stared down the explanation in the book and still can't grasp how this problem should be worked out.
Cost of 100 batteries = $q
Cost of 1 battery = $ (q/100)
It is given that the selling price of 1 battery is 50 percent above the original cost per battery, so the selling price of 1 battery = (q/100) + (q/100)*(50/100) = (q/100) + (q/200) = 3q/200

The correct answer is A.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/

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 Sep 19, 2011 7:21 pm
razorback wrote:A dealer originally bought 100 identical batteries at a total cost of q dollars. If each battery was sold at 50 percent above the original cost per battery, then, in terms of q, for how many dollars was each battery sold?

(A) 3q/200 (read: 3q all over 200)
(B) 3q/2 (read: 3q all over 2)
(C) 150q
(D) q/100 + 50 (read q over 100, then add 50)
(E) 150/q

Official answer soon.

This question is #84/230 from the Official Guide, which I interpret as "slightly below average" difficulty. I have stared down the explanation in the book and still can't grasp how this problem should be worked out.
Let q = 200.
Thus, 100 batteries were bought for a total cost of 200.
Cost per battery = 200/100 = 2.
Selling price = 2 + .5(2) = 3. This is our target.

Now we plug q=200 into the answers to see which yields our target of 3.

Only answer choice A works:
3q/200 = (3*200)/200 = 3.

The correct answer is A.
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

Junior | Next Rank: 30 Posts
Posts: 28
Joined: Mon Aug 29, 2011 6:43 pm
Thanked: 1 times

by razorback » Thu Sep 22, 2011 7:01 pm
Ok that makes a lot of sense, thanks.

User avatar
Senior | Next Rank: 100 Posts
Posts: 44
Joined: Sun Aug 21, 2011 1:47 am
Thanked: 3 times

by leumas » Fri Sep 23, 2011 8:14 am
razorback wrote:A dealer originally bought 100 identical batteries at a total cost of q dollars. If each battery was sold at 50 percent above the original cost per battery, then, in terms of q, for how many dollars was each battery sold?

(A) 3q/200 (read: 3q all over 200)
(B) 3q/2 (read: 3q all over 2)
(C) 150q
(D) q/100 + 50 (read q over 100, then add 50)
(E) 150/q

Official answer soon.

This question is #84/230 from the Official Guide, which I interpret as "slightly below average" difficulty. I have stared down the explanation in the book and still can't grasp how this problem should be worked out.
Cost = q/100
Profit =50%
Selling price=1.5q/100
Answer doesn't have this option: Multiply by 2.

3q/200= Answer

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7223
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Wed Jun 24, 2015 3:16 am
razorback wrote:A dealer originally bought 100 identical batteries at a total cost of q dollars. If each battery was sold at 50 percent above the original cost per battery, then, in terms of q, for how many dollars was each battery sold?

(A) 3q/200 (read: 3q all over 200)
(B) 3q/2 (read: 3q all over 2)
(C) 150q
(D) q/100 + 50 (read q over 100, then add 50)
(E) 150/q

Official answer soon.

This question is #84/230 from the Official Guide, which I interpret as "slightly below average" difficulty. I have stared down the explanation in the book and still can't grasp how this problem should be worked out.
Solution:

We are given that 100 batteries cost a TOTAL of q dollars. We are also given that EACH battery was sold at 50% above the original cost. The first thing we must do is create an equation for q. Remember that q is the TOTAL COST. So if we make b = the original cost per battery we can say:

100 x b = q

b = q/100

We now have the original cost per battery in terms of q. Next, we determine the selling price when we increase the cost by 50%. To calculate this increase we simply multiply q/100 by 1.5. We have:

(q/100) x 1.5

(q/100) x 3/2 = 3q/200

Answer: A

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Wed Jun 24, 2015 6:20 am
Brent Hanneson - Creator of GMATPrepNow.com
Image