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

It is currently 14 Oct 2019, 03:58

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

A box contains only red chips, green chips and blue chips. If a chip i

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

Hide Tags

Find Similar Topics 
Senior Manager
Senior Manager
User avatar
P
Joined: 17 Oct 2016
Posts: 257
Location: India
Concentration: General Management, Healthcare
GMAT 1: 640 Q40 V38
GMAT 2: 680 Q48 V35
GPA: 3.05
WE: Pharmaceuticals (Health Care)
Reviews Badge
A box contains only red chips, green chips and blue chips. If a chip i  [#permalink]

Show Tags

New post 27 Aug 2017, 19:51
4
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

70% (00:44) correct 30% (00:51) wrong based on 119 sessions

HideShow timer Statistics

A box contains only red chips, green chips and blue chips. If a chip is randomly selected from the box, what is the probability that the chip is either red or green?

A. The probability of selecting green chip is 1/3

B. The Probability of selecting a blue chip is 1/7

_________________
_____________________
Chasing the dragon
Math Expert
avatar
V
Joined: 02 Aug 2009
Posts: 7952
Re: A box contains only red chips, green chips and blue chips. If a chip i  [#permalink]

Show Tags

New post 27 Aug 2017, 20:26
1
fitzpratik wrote:
A box contains only red chips, green chips and blue chips. If a chip is randomly selected from the box, what is the probability that the chip is either red or green?

A. The probability of selecting green chip is 1/3

B. The Probability of selecting a blue chip is 1/7


hi..

I am sure these type of Qs would have been discussed in various ways in the forum..

in such Qs main point is to remember: - 3 things probability that it is 3rd item is equal to probability it is not the FIRST two AND vice-versa..


either red or green..
1) we require to know each of red and green
2) OR we require to know about blue


A. The probability of selecting green chip is 1/3
we require to know red too..
insuff

B. The Probability of selecting a blue chip is 1/7
sufficient ans 1-1/7=6/7

B
_________________
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58315
Re: A box contains only red chips, green chips and blue chips. If a chip i  [#permalink]

Show Tags

New post 28 Aug 2017, 02:14
chetan2u wrote:
fitzpratik wrote:
A box contains only red chips, green chips and blue chips. If a chip is randomly selected from the box, what is the probability that the chip is either red or green?

A. The probability of selecting green chip is 1/3

B. The Probability of selecting a blue chip is 1/7


hi..

I am sure these type of Qs would have been discussed in various ways in the forum..

in such Qs main point is to remember: - 3 things probability that it is 3rd item is equal to probability it is not the FIRST two AND vice-versa..


either red or green..
1) we require to know each of red and green
2) OR we require to know about blue


A. The probability of selecting green chip is 1/3
we require to know red too..
insuff

B. The Probability of selecting a blue chip is 1/7
sufficient ans 1-1/7=6/7

B


Yes, this is a copy of the following OG question: https://gmatclub.com/forum/a-box-contai ... 44131.html

Similar question from Magoosh: https://gmatclub.com/forum/a-box-contai ... 95322.html
_________________
Senior Manager
Senior Manager
User avatar
P
Joined: 29 Jun 2017
Posts: 424
GPA: 4
WE: Engineering (Transportation)
GMAT ToolKit User Reviews Badge
Re: A box contains only red chips, green chips and blue chips. If a chip i  [#permalink]

Show Tags

New post 28 Aug 2017, 02:44
Ans is B
see the pic for solution.
Attachments

IMG_5248.JPG
IMG_5248.JPG [ 2.43 MiB | Viewed 1655 times ]


_________________
Give Kudos for correct answer and/or if you like the solution.
Manager
Manager
avatar
B
Joined: 07 Jun 2017
Posts: 100
Re: A box contains only red chips, green chips and blue chips. If a chip i  [#permalink]

Show Tags

New post 28 Aug 2017, 20:02
good question, i fall into a little trap
i thought we need to get the % of red
but actually we just need to subtract the blue portion then we can get green and red
Senior Manager
Senior Manager
User avatar
P
Joined: 29 Jun 2017
Posts: 424
GPA: 4
WE: Engineering (Transportation)
GMAT ToolKit User Reviews Badge
Re: A box contains only red chips, green chips and blue chips. If a chip i  [#permalink]

Show Tags

New post 28 Aug 2017, 23:01
pclawong wrote:
good question, i fall into a little trap
i thought we need to get the % of red
but actually we just need to subtract the blue portion then we can get green and red


Always stick to fundamentals and go by procedure and you will never go wrong. I hope your doubt is clear.
_________________
Give Kudos for correct answer and/or if you like the solution.
CEO
CEO
User avatar
V
Joined: 12 Sep 2015
Posts: 3990
Location: Canada
Re: A box contains only red chips, green chips and blue chips. If a chip i  [#permalink]

Show Tags

New post 12 Aug 2018, 06:05
Top Contributor
fitzpratik wrote:
A box contains only red chips, green chips and blue chips. If a chip is randomly selected from the box, what is the probability that the chip is either red or green?

A. The probability of selecting green chip is 1/3

B. The Probability of selecting a blue chip is 1/7


Target question: What is the probability that the chip is either red or green?

Given: The box contains only red chips, green chips and blue chips

Statement 1: The probability of selecting green chip is 1/3
This tells us that 1/3 of the chips are GREEN, but there's no information about the RED chips.

Consider these two possible cases:
Case a: There are 6 chips in total. 2 chips are green, and 2 chips are red. In this case, the answer to the target question is P(chip is red or green) = 4/6
Case b: There are 6 chips in total. 2 chips are green, and 3 chips are red. In this case, the answer to the target question is P(chip is red or green) = 5/6
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: The probability of selecting a blue chip is 1/7
This also tells us that the probability of selecting a NON-BLUE chip is 6/7
Since the box contains only red chips, green chips and blue chips, then selecting a NON-BLUE chip is the same as selecting either a RED chip OR a green chip
In other other words, P(select NON-BLUE chip) = P(selecting either a RED chip OR a green chip)
So, the answer to the target question is P(chip is red or green) = 6/7

Answer: B

Cheers,
Brent
_________________
Test confidently with gmatprepnow.com
Image
GMAT Club Bot
Re: A box contains only red chips, green chips and blue chips. If a chip i   [#permalink] 12 Aug 2018, 06:05
Display posts from previous: Sort by

A box contains only red chips, green chips and blue chips. If a chip i

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





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