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

It is currently 21 Oct 2019, 13:37

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 pens, pencils, and pads. If an item is randomly se

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58396
A box contains only pens, pencils, and pads. If an item is randomly se  [#permalink]

Show Tags

New post 16 Aug 2019, 01:47
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

55% (00:45) correct 45% (00:53) wrong based on 75 sessions

HideShow timer Statistics

Intern
Intern
avatar
B
Joined: 25 Mar 2017
Posts: 28
Location: India
GMAT 1: 650 Q49 V31
GMAT 2: 700 Q47 V39
GPA: 3.1
Reviews Badge
Re: A box contains only pens, pencils, and pads. If an item is randomly se  [#permalink]

Show Tags

New post 18 Aug 2019, 05:01
Let P(Pencil) be probability of finding a pencil. Similarly we will use P(Pen) and P(Pad) in our solution.
What we need to find is P ( either Pencil or Pad).
P(either Pencil or Pad) = P( not finding a Pen)

Statement 1
P(Pad)=1/4
It does not help us find P(Pencil)
Not sufficient

Statement 2
P(Pen)=1/3
We have P (not finding a Pen) = 1 - P(Pen)= 1 - 1/3 = 2/3
SUfficient

Answer: B
CrackVerbal Quant Expert
User avatar
G
Joined: 12 Apr 2019
Posts: 268
Re: A box contains only pens, pencils, and pads. If an item is randomly se  [#permalink]

Show Tags

New post 20 Aug 2019, 04:06
The event of selecting a pencil is mutually exclusive to the event of selecting a pad. Therefore, the probability of selecting a pencil or a pad will be the cumulative of the two probabilities.

From statement I, we know the probability of selecting a pad, but not for the pencil. Statement I is insufficient.
Answer options A and D can be eliminated. Possible answer options are B, C or E.

From statement II we know that the probability of selecting a pen is \(\frac{1}{3}\). Therefore, the cumulative probability of selecting a pencil or a pad = 1 – \(\frac{1}{3}\) = \(\frac{2}{3}\).
Statement II is sufficient. Answer options C and E can be eliminated.

The correct answer option is B.

Hope this helps!
_________________
SVP
SVP
User avatar
P
Joined: 03 Jun 2019
Posts: 1737
Location: India
Premium Member Reviews Badge CAT Tests
Re: A box contains only pens, pencils, and pads. If an item is randomly se  [#permalink]

Show Tags

New post 20 Aug 2019, 05:07
Bunuel wrote:
A box contains only pens, pencils, and pads. If an item is randomly selected from the box, what is the probability that the item will be either a pencil or a pad?

(1) The probability that the item will be pad is 1/4.

(2) The probability that the chip will be pen is 1/3.


chip should be replaced with item
_________________
"Success is not final; failure is not fatal: It is the courage to continue that counts."

Please provide kudos if you like my post. Kudos encourage active discussions.

My GMAT Resources: -

Efficient Learning
All you need to know about GMAT quant

Tele: +91-11-40396815
Mobile : +91-9910661622
E-mail : kinshook.chaturvedi@gmail.com
SVP
SVP
User avatar
P
Joined: 03 Jun 2019
Posts: 1737
Location: India
Premium Member Reviews Badge CAT Tests
Re: A box contains only pens, pencils, and pads. If an item is randomly se  [#permalink]

Show Tags

New post 20 Aug 2019, 05:12
Bunuel wrote:
A box contains only pens, pencils, and pads. If an item is randomly selected from the box, what is the probability that the item will be either a pencil or a pad?

(1) The probability that the item will be pad is 1/4.

(2) The probability that the chip will be pen is 1/3.


Given: A box contains only pens, pencils, and pads.

Asked: If an item is randomly selected from the box, what is the probability that the item will be either a pencil or a pad?

(1) The probability that the item will be pad is 1/4.
Probability that the item will be pencil is unknown
NOT SUFFICIENT

(2) The probability that the item will be pen is 1/3.
A box contains only pens, pencils, and pads.
No of either pencil or a pad = Total - no of pens
the probability that the item will be either a pencil or a pad = 1 - The probability that the item will be pen is 1/3 = 2/3
SUFFICIENT

IMO B
_________________
"Success is not final; failure is not fatal: It is the courage to continue that counts."

Please provide kudos if you like my post. Kudos encourage active discussions.

My GMAT Resources: -

Efficient Learning
All you need to know about GMAT quant

Tele: +91-11-40396815
Mobile : +91-9910661622
E-mail : kinshook.chaturvedi@gmail.com
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58396
Re: A box contains only pens, pencils, and pads. If an item is randomly se  [#permalink]

Show Tags

New post 17 Sep 2019, 05:10
Bunuel wrote:
A box contains only pens, pencils, and pads. If an item is randomly selected from the box, what is the probability that the item will be either a pencil or a pad?

(1) The probability that the item will be pad is 1/4.

(2) The probability that the item will be pen is 1/3.


Official Explanation



We have an abundance of pens, pencils and pads. The probability that an item will be a pencil or a pad is (pencil or pen) = P(pencil) + P(pen), the sum of the individual probabilities, or else P(pencil or pen) = 1 - P(pen) , the probably that the item chosen is not a pen. On to the statements, separately first.

Statement (1) doesn't fit either case for sufficiency. The probability of a pencil could be 1/2, say, or 1/4, yielding different results to the question. Insufficient.

Statement (2) gives us sufficient information. The probability that the item is not a pen is 2/3, so the probability that the item is either a pencil or a pad is 2/3. Sufficient.

The correct answer is (B).
_________________
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58396
Re: A box contains only pens, pencils, and pads. If an item is randomly se  [#permalink]

Show Tags

New post 17 Sep 2019, 05:10
GMAT Club Bot
Re: A box contains only pens, pencils, and pads. If an item is randomly se   [#permalink] 17 Sep 2019, 05:10
Display posts from previous: Sort by

A box contains only pens, pencils, and pads. If an item is randomly se

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





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