GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 21 Oct 2019, 03:30

### 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

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

# A stock broker recommends a portfolio of 2 Information Technology stoc

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

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58421
A stock broker recommends a portfolio of 2 Information Technology stoc  [#permalink]

### Show Tags

02 Oct 2018, 02:07
00:00

Difficulty:

15% (low)

Question Stats:

77% (01:33) correct 23% (02:11) wrong based on 87 sessions

### HideShow timer Statistics

A stock broker recommends a portfolio of 2 Information Technology stocks, 4 Retail stocks, and 2 e-commerce stocks. If the broker can choose from 4 Information Technology stocks, 5 Retail stocks, and 3 e-commerce stocks, how many different portfolios of 8 stocks are possible?

(A) 9
(B) 24
(C) 60
(D) 90
(E) 120

_________________
Manager
Joined: 19 Apr 2017
Posts: 172
Concentration: General Management, Sustainability
Schools: ESSEC '22
GPA: 3.9
WE: Operations (Hospitality and Tourism)
A stock broker recommends a portfolio of 2 Information Technology stoc  [#permalink]

### Show Tags

05 Oct 2018, 12:05
Tip: You use combination when the question asks you to find unordered collection of k objects taken from a set of n distinct objects. The number of ways how we can choose k objects out of n distinct objects is denoted as: nCk (read as From n objects choose k objects)

Tip 2: Simultaneous events are always multiplied

$$4C2*5C4*3C2=6*5*3=90$$
Intern
Joined: 30 Sep 2018
Posts: 9
Schools: DeGroote'21
Re: A stock broker recommends a portfolio of 2 Information Technology stoc  [#permalink]

### Show Tags

09 Oct 2018, 13:40
AvidDreamer09 wrote:
Tip: You use combination when the question asks you to find unordered collection of k objects taken from a set of n distinct objects. The number of ways how we can choose k objects out of n distinct objects is denoted as: nCk (read as From n objects choose k objects)

Tip 2: Simultaneous events are always multiplied

$$4C2*5C4*3C2=6*5*3=90$$

Isn't 4C2 = 12, not 6?

Can you please explain?
Intern
Joined: 21 Sep 2018
Posts: 2
Re: A stock broker recommends a portfolio of 2 Information Technology stoc  [#permalink]

### Show Tags

09 Oct 2018, 20:23
1
zwander wrote:
AvidDreamer09 wrote:
Tip: You use combination when the question asks you to find unordered collection of k objects taken from a set of n distinct objects. The number of ways how we can choose k objects out of n distinct objects is denoted as: nCk (read as From n objects choose k objects)

Tip 2: Simultaneous events are always multiplied

$$4C2*5C4*3C2=6*5*3=90$$

Isn't 4C2 = 12, not 6?

Can you please explain?

nCk = n!/[(k!)*(n-k)!]

So in this case, 4C2 = 4!/[(2!)*(2!)] = 3! (because 2!*2! = 4, so 4! becomes 3!) = 6.

I hope that helps.
Manager
Joined: 19 Apr 2017
Posts: 172
Concentration: General Management, Sustainability
Schools: ESSEC '22
GPA: 3.9
WE: Operations (Hospitality and Tourism)
Re: A stock broker recommends a portfolio of 2 Information Technology stoc  [#permalink]

### Show Tags

09 Oct 2018, 21:13
1
zwander wrote:
AvidDreamer09 wrote:
Tip: You use combination when the question asks you to find unordered collection of k objects taken from a set of n distinct objects. The number of ways how we can choose k objects out of n distinct objects is denoted as: nCk (read as From n objects choose k objects)

Tip 2: Simultaneous events are always multiplied

$$4C2*5C4*3C2=6*5*3=90$$

Isn't 4C2 = 12, not 6?

Can you please explain?

The Formula for combination is $$nCr = \frac{n!}{(n-r)*r!]}$$
$$4C2 = \frac{4!}{[(4-2!)*(2!)]} = \frac{4*3*2*1}{2*1*2*1}$$

Ive been using this link this to learn...it did help me... you might want to take a look.

https://gmatclub.com/forum/combination- ... 56486.html
CR Forum Moderator
Joined: 25 Apr 2018
Posts: 637
GMAT 1: 680 Q49 V34
Re: A stock broker recommends a portfolio of 2 Information Technology stoc  [#permalink]

### Show Tags

09 Oct 2018, 22:12
We can use combinations to solve this

4C2*5C4*3C2

=6*5*3
=90

Option D
_________________
Please give kudos if you found my posts helpful!

Project CR Butler - 2 CR's everyday
Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8117
Location: United States (CA)
Re: A stock broker recommends a portfolio of 2 Information Technology stoc  [#permalink]

### Show Tags

13 Oct 2018, 18:34
Bunuel wrote:
A stock broker recommends a portfolio of 2 Information Technology stocks, 4 Retail stocks, and 2 e-commerce stocks. If the broker can choose from 4 Information Technology stocks, 5 Retail stocks, and 3 e-commerce stocks, how many different portfolios of 8 stocks are possible?

(A) 9
(B) 24
(C) 60
(D) 90
(E) 120

The number of ways to select the information technology stocks is 4C2:

4C2 = (4 x 3)/2! = 6

The number of ways to select the retail stocks is 5C4:

5C4 = 5

The number of ways to select the e-commerce stocks is 3C2:

3C2 = 3

So the total number of ways of selecting the portfolio of 8 stocks is 6 x 5 x 3 = 90.

_________________

# Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Re: A stock broker recommends a portfolio of 2 Information Technology stoc   [#permalink] 13 Oct 2018, 18:34
Display posts from previous: Sort by

# A stock broker recommends a portfolio of 2 Information Technology stoc

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

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