GMAT Changed on April 16th - Read about the latest changes here

It is currently 27 May 2018, 18:07

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

A customer wants to buy a total of 8kg rice of two varieties- A an

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

Hide Tags

Expert Post
1 KUDOS received
e-GMAT Representative
User avatar
G
Joined: 04 Jan 2015
Posts: 1257
A customer wants to buy a total of 8kg rice of two varieties- A an [#permalink]

Show Tags

New post Updated on: 27 Apr 2018, 06:04
1
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

60% (01:06) correct 40% (01:22) wrong based on 60 sessions

HideShow timer Statistics

3 deadly mistakes you must avoid in Probability - Exercise Question #2


2- A customer wants to buy a total of 8kg rice of two varieties- A and B. If he can buy each type of rice only in integral multiples of 1 kg then what is the probability that he will buy at least 2 kg rice of each variety?

Options
    a) 1/3
    b) 4/9
    c) 5/9
    d) 5/8
    e) 2/3

To solve question 3:Question 3


To read the article: 3 deadly mistakes you must avoid in Probability

_________________












| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com


Originally posted by EgmatQuantExpert on 26 Apr 2018, 05:30.
Last edited by EgmatQuantExpert on 27 Apr 2018, 06:04, edited 2 times in total.
Expert Post
e-GMAT Representative
User avatar
G
Joined: 04 Jan 2015
Posts: 1257
A customer wants to buy a total of 8kg rice of two varieties- A an [#permalink]

Show Tags

New post Updated on: 29 Apr 2018, 02:35

Solution




Given:

• The customer wants to buy 8 kg of rice.
• The rice is of two types- A and B.
• The customer can buy each type of rice only in integral multiples of a kg.

To find:
• The probability such that the customer buys 2kg rice of each variety.

Approach and Working:

We can solve this problem from two methods:

    • By calculating the probabilities of the independent cases
      o 2 kg Rice A and 6 kg rice B
      o 3 kg Rice A and 5 kg rice B
      o 4 kg Rice A and 4 kg rice B
      o 5 kg Rice A and 3 kg rice B
      o 6 kg Rice A and 2 kg rice B

    • By non-event method
      o P (customer buys 2kg rice of each variety) = 1- P(customer buys 0 kg rice of one variety)- P(customer buys 1 kg rice of one variety)

Clearly, the 2nd method reduces a lot of calculation.

P(customer buys 0 kg rice of one variety):

    • There are 2 possible ways in which he can buy 0 kg rice of one variety.
      o When he buys 8 kg rice of type A.
      o When he buys 8 kg rice of type A.
    • Thus, P (customer buys 0 kg rice of one variety) = 2/9

P(customer buys 1 kg rice of one variety):
    • There are 2 possible ways in which he can buy 1 kg rice of one variety.
      o When he buys 1 kg rice of type A and 1 kg rice of type B.
      o When he buys 1 kg rice of type B and 7 kg rice of type B.
    • Thus, P (customer buys 0 kg rice of one variety) = 2/9

Hence, P (customer buys 2kg rice of each variety) = 1- 2/9-2/9= 5/9
Hence, the correct answer is option C.

Answer: C
_________________












| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com


Originally posted by EgmatQuantExpert on 26 Apr 2018, 05:31.
Last edited by EgmatQuantExpert on 29 Apr 2018, 02:35, edited 1 time in total.
Manager
Manager
avatar
S
Joined: 25 Apr 2016
Posts: 56
Re: A customer wants to buy a total of 8kg rice of two varieties- A an [#permalink]

Show Tags

New post 26 Apr 2018, 05:40
Total no. of cases lie from the range of (8,0) to (0,8) => 9 cases
and no. of favorable ones would be (2,6),(3,5),(4,4),(5,3), and (6,2)
=> probability=5/9
Manager
Manager
avatar
B
Joined: 04 Feb 2016
Posts: 68
Location: India
Concentration: Technology, Marketing
GPA: 3.7
WE: Sales (Computer Software)
CAT Tests
Re: A customer wants to buy a total of 8kg rice of two varieties- A an [#permalink]

Show Tags

New post 27 Apr 2018, 01:01
Integral solutions to the equation A+B = x = x+2-1 C 1

Since A , B have to be at least 2 each the equation becomes A+B=4.
Number of solutions = 5C1 = 5.

Total possible solutions = 9C1 = 9.

Hence C.
_________________

GMAT1 650 Q48 V32.

Manager
Manager
User avatar
B
Joined: 26 Sep 2017
Posts: 78
CAT Tests
Re: A customer wants to buy a total of 8kg rice of two varieties- A an [#permalink]

Show Tags

New post 27 Apr 2018, 03:27
attari92 wrote:
Total no. of cases lie from the range of (8,0) to (0,8) => 9 cases
and no. of favorable ones would be (2,6),(3,5),(4,4),(5,3), and (6,2)
=> probability=5/9


hi i have a confusion...here..

how one can take (8,0) and (0,8)
it is given a person need two take 8 kg of rice of two varieties...there must be two varieties in 0,8 and 8,0 the variety is only one..
Manager
Manager
avatar
S
Joined: 25 Apr 2016
Posts: 56
Re: A customer wants to buy a total of 8kg rice of two varieties- A an [#permalink]

Show Tags

New post 27 Apr 2018, 04:04
viv007 wrote:
attari92 wrote:
Total no. of cases lie from the range of (8,0) to (0,8) => 9 cases
and no. of favorable ones would be (2,6),(3,5),(4,4),(5,3), and (6,2)
=> probability=5/9


hi i have a confusion...here..

how one can take (8,0) and (0,8)
it is given a person need two take 8 kg of rice of two varieties...there must be two varieties in 0,8 and 8,0 the variety is only one..





I put the two varieties in an ordered pair, just a gesticulation of representation. And, there isn't anything wrong in considering range from (8,0) to (0,8) as it symbolizes the entire sample space.
Expert Post
e-GMAT Representative
User avatar
G
Joined: 04 Jan 2015
Posts: 1257
Re: A customer wants to buy a total of 8kg rice of two varieties- A an [#permalink]

Show Tags

New post 29 Apr 2018, 02:36
Hey everyone,

The official answer to the question has been posted.

Regards,
Ashutosh
_________________












| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

1 KUDOS received
Manager
Manager
User avatar
B
Joined: 29 Dec 2017
Posts: 147
Location: United States
Concentration: Marketing, Technology
GMAT 1: 630 Q44 V33
GPA: 3.25
WE: Marketing (Telecommunications)
A customer wants to buy a total of 8kg rice of two varieties- A an [#permalink]

Show Tags

New post 30 Apr 2018, 18:42
1
This post received
KUDOS
EgmatQuantExpert wrote:
Hey everyone,

The official answer to the question has been posted.

Regards,
Ashutosh


Can you rephrase the question to "he needs to buy 8 kg. There are two kinds of rice..."? Otherwise the question sounds ambiguous, since he have to buy 8 kg of both kinds, and people are confused. Thanks
_________________

I'm looking for a study buddy in NY, who is aiming at 700+. PM me.

A customer wants to buy a total of 8kg rice of two varieties- A an   [#permalink] 30 Apr 2018, 18:42
Display posts from previous: Sort by

A customer wants to buy a total of 8kg rice of two varieties- A an

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


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.