Last visit was: 21 May 2024, 15:36 It is currently 21 May 2024, 15:36
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
SORT BY:
Date
Tags:
Show Tags
Hide Tags
User avatar
Intern
Intern
Joined: 07 Jan 2011
Posts: 13
Own Kudos [?]: 13 [6]
Given Kudos: 4
Send PM
Retired Moderator
Joined: 16 Nov 2010
Posts: 908
Own Kudos [?]: 1178 [0]
Given Kudos: 43
Location: United States (IN)
Concentration: Strategy, Technology
Send PM
User avatar
Intern
Intern
Joined: 07 Jan 2011
Posts: 13
Own Kudos [?]: 13 [0]
Given Kudos: 4
Send PM
User avatar
Senior Manager
Senior Manager
Joined: 01 Feb 2011
Posts: 309
Own Kudos [?]: 324 [1]
Given Kudos: 42
Send PM
Re: Shipment of batteries (source gmat paper test) [#permalink]
1
Kudos
1. Not sufficient.

sample of 10 items has 1 defective item. that doesnt tell us anything about the rest of the 4990 items.we may or may not have defective items in the rest.

2. Not sufficient.

sample of 100 items has 3 defective items. that doesnt tell us anything about the rest of 3900 items. we may or may not have defective items in the rest.

together , still not sufficient as we only about the defective items in a 100 item sample . we still dont know aything about the rest of the items.

Answer is E.
User avatar
Manager
Manager
Joined: 10 Nov 2010
Posts: 129
Own Kudos [?]: 2618 [0]
Given Kudos: 22
Location: India
Concentration: Strategy, Operations
GMAT 1: 520 Q42 V19
GMAT 2: 540 Q44 V21
WE:Information Technology (Computer Software)
Send PM
Re: Shipment of batteries (source gmat paper test) [#permalink]
subhashghosh wrote:
(1) indicates 10% of batteries are defective

(2) indicates 3% of batteries are defective.

However, these are inconsistent, so we don't know for sure which of these two is full and accurate representation of shipment quality.

Answer - E.



Is this interpretation correct
Math Expert
Joined: 02 Sep 2009
Posts: 93373
Own Kudos [?]: 625628 [3]
Given Kudos: 81918
Send PM
Re: Shipment of batteries (source gmat paper test) [#permalink]
3
Kudos
Expert Reply
GMATD11 wrote:
subhashghosh wrote:
(1) indicates 10% of batteries are defective

(2) indicates 3% of batteries are defective.

However, these are inconsistent, so we don't know for sure which of these two is full and accurate representation of shipment quality.

Answer - E.



Is this interpretation correct


No, it's not. We can not extrapolate the data on some particular sample to all shipment.

What was the number of defective batteries in a shipment of 4000 batteries ?

(1) In a particular sample of 10 batteries selected from the shipment 1 was defective --> just tells us that there is at least 1 defective battery in the shipment of 4000 batteries. Not sufficient.

(2) In a particulare sample of 100 batteries selected from the shipment, 3 were defective --> just tells us that there are at least 3 defective batteries in the shipment of 4000 batteries. Not sufficient.

(1)+(2) All we know is that there are at least 3 defective batteries in the shipment of 4000 batteries. Not sufficient.

Answer; E.
Intern
Intern
Joined: 21 Jan 2018
Posts: 42
Own Kudos [?]: 22 [0]
Given Kudos: 42
Location: India
GPA: 2.85
WE:Consulting (Consulting)
Send PM
Re: What was the number of defective batteries in a shipment of [#permalink]
patanahi wrote:
What was the number of defective batteries in a shipment of 4000 batteries ?

(1) In a particular sample of 10 batteries selected from the shipment 1 was defective.
(2) In a particulare sample of 100 batteries selected from the shipment, 3 were defective.


Option E

Because the question does not mention that the sample is an actual representaion of the whole lot.
GMAT Club Legend
GMAT Club Legend
Joined: 12 Sep 2015
Posts: 6817
Own Kudos [?]: 30289 [0]
Given Kudos: 799
Location: Canada
Send PM
Re: What was the number of defective batteries in a shipment of [#permalink]
Expert Reply
Top Contributor
patanahi wrote:
What was the number of defective batteries in a shipment of 4000 batteries ?

(1) In a particular sample of 10 batteries selected from the shipment 1 was defective.
(2) In a particulare sample of 100 batteries selected from the shipment, 3 were defective.


Target question: What was the number of defective batteries in a shipment of 4000 batteries?

Statement 1: In a particular sample of 10 batteries selected from the shipment, 1 was defective.
Don't make the mistake of assuming that this means 1/10 of ALL batteries are defective. There's no reason to assume this.
There are several scenarios that satisfy statement 1. Here are two:
Case a: There's 1 defective battery in the 10-battery sample, and 0 defective batteries in the remaining 3990 batteries. In this case, the answer to the target question is there's ONE defective battery in the shipment of 4000 batteries
Case b: There's 1 defective battery in the 10-battery sample, and 2 defective batteries in the remaining 3990 batteries. In this case, the answer to the target question is there are THREE defective batteries in the shipment of 4000 batteries
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: In a particular sample of 100 batteries selected from the shipment, 3 were defective.
There are several scenarios that satisfy statement 2. Here are two:
Case a: There are 3 defective batteries in the 100-battery sample, and 0 defective batteries in the remaining 3900 batteries. In this case, the answer to the target question is there are THREE defective batteries in the shipment of 4000 batteries
Case b: There are 3 defective batteries in the 100-battery sample, and 2 defective batteries in the remaining 3900 batteries. In this case, the answer to the target question is there are FIVE defective batteries in the shipment of 4000 batteries
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
There are several scenarios that satisfy BOTH statements. Here are two:
Case a: 1 defective battery in 1st sample, 3 defective batteries in 2nd sample, and 0 defective batteries in the remaining 3890 batteries. In this case, the answer to the target question is there are FOUR defective batteries in the shipment of 4000 batteries
Case b: 1 defective battery in 1st sample, 3 defective batteries in 2nd sample, and 4 defective batteries in the remaining 3890 batteries. In this case, the answer to the target question is there are EIGHT defective batteries in the shipment of 4000 batteries
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E

Cheers,
Brent
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 33140
Own Kudos [?]: 829 [0]
Given Kudos: 0
Send PM
Re: What was the number of defective batteries in a shipment of [#permalink]
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
GMAT Club Bot
Re: What was the number of defective batteries in a shipment of [#permalink]
Moderator:
Math Expert
93373 posts