It is currently 19 Oct 2017, 17:25

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Lady Edith bought several necklaces at the jewelry store, and each nec

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

1 KUDOS received
VP
VP
User avatar
V
Status: Preparing for the GMAT
Joined: 02 Nov 2016
Posts: 1236

Kudos [?]: 1042 [1], given: 538

Location: Pakistan
GPA: 3.4
Premium Member CAT Tests
Lady Edith bought several necklaces at the jewelry store, and each nec [#permalink]

Show Tags

New post 17 Sep 2017, 11:40
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

78% (01:16) correct 22% (00:29) wrong based on 23 sessions

HideShow timer Statistics

Lady Edith bought several necklaces at the jewelry store, and each necklace cost 16 dollars. Lady Mary also purchased several necklaces, at a cost of $20 each. If the ratio of the number of necklaces Lady Edith purchased to the number of necklaces Lady Mary purchased is 3 to 2, what is the average cost of the necklaces purchased by Lady Edith and Lady Mary?


A 16.7
B 17.1
C 17.6
D 17.9
E 18.2
[Reveal] Spoiler: OA

_________________

Official PS Practice Questions
Press +1 Kudos if this post is helpful

Kudos [?]: 1042 [1], given: 538

2 KUDOS received
Director
Director
avatar
P
Joined: 22 May 2016
Posts: 814

Kudos [?]: 264 [2], given: 552

Lady Edith bought several necklaces at the jewelry store, and each nec [#permalink]

Show Tags

New post 18 Sep 2017, 11:10
2
This post received
KUDOS
SajjadAhmad wrote:
Lady Edith bought several necklaces at the jewelry store, and each necklace cost 16 dollars. Lady Mary also purchased several necklaces, at a cost of $20 each. If the ratio of the number of necklaces Lady Edith purchased to the number of necklaces Lady Mary purchased is 3 to 2, what is the average cost of the necklaces purchased by Lady Edith and Lady Mary?


A 16.7
B 17.1
C 17.6
D 17.9
E 18.2

Great question. A bit tricky. I used weighted average.

Average cost overall =
(Cost\(_{E}\))(Weight\(_{E}\)) + (Cost\(_{M}\))(Weight\(_{M}\)) / (Total Weight)

Cost = cost per necklace, for E and M

Weight = number of necklaces as portion of all necklaces purchased

To derive weight for each person, use ratio of number of necklaces purchased:

\(\frac{E}{M} = \frac{3x}{2x}\)

You could use this ratio a few ways. Easier for me: let x = 1. E buys 3 necklaces. M buys 2. Total # bought = total weight = 5:

\(\frac{16(3) + 20(2)}{5}\) =

\(\frac{88}{5}\) = 17.6

If substitution is preferred, use E = \(\frac{3}{2}\)M (Ms will cancel)

Total weight is M + \(\frac{3}{2}\)M = \(\frac{5}{2}\)M

\(\frac{(16)(3/2) + 20(1)}{2.5}\) = \(\frac{44}{2.5}\) = 17.6

ANSWER C

Kudos [?]: 264 [2], given: 552

Lady Edith bought several necklaces at the jewelry store, and each nec   [#permalink] 18 Sep 2017, 11:10
Display posts from previous: Sort by

Lady Edith bought several necklaces at the jewelry store, and each nec

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.