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

 It is currently 23 Feb 2019, 05:00

### 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

## Events & Promotions

###### Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
• ### Free GMAT RC Webinar

February 23, 2019

February 23, 2019

07:00 AM PST

09:00 AM PST

Learn reading strategies that can help even non-voracious reader to master GMAT RC. Saturday, February 23rd at 7 AM PT
• ### FREE Quant Workshop by e-GMAT!

February 24, 2019

February 24, 2019

07:00 AM PST

09:00 AM PST

Get personalized insights on how to achieve your Target Quant Score.

# D01-23

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

### Hide Tags

Manager
Joined: 02 Nov 2015
Posts: 165
GMAT 1: 640 Q49 V29

### Show Tags

20 Aug 2017, 09:57
Indeed a high quality question that tests our skills of understanding prime numbers , reciprocals and divisibility.

Though I am not qualified enough to pass any comment or remark on any question, but one thing I am sure is that almost all the questions of Bunuel are truly excellent...

Sent from my Lenovo TAB S8-50LC using GMAT Club Forum mobile app
Math Expert
Joined: 02 Sep 2009
Posts: 53066

### Show Tags

21 Aug 2017, 02:43
sharmapallavi wrote:
I think this is a poor-quality question and I don't agree with the explanation. For GMAT or OTHERWISE, a SET never has any repetitions. You should have mentioned a LIST instead of a SET in this question.

Yes, you are right. Edited as suggested. Thank you.
_________________
Intern
Joined: 04 Sep 2017
Posts: 22
Location: United States
Concentration: Finance
GMAT 1: 610 Q36 V36
GMAT 2: 680 Q40 V36
GPA: 3.3
WE: Consulting (Mutual Funds and Brokerage)

### Show Tags

10 Nov 2017, 13:50
I can certainly see the logic in the explanation with this question, but I answered E. My basis for E is that all the terms could be 1/5 in which case the median is 1/5. My understanding of the wording of the question is the median has to be less than 1/5 to give a hard yes, but if you can have 1/5 as well as 1/2 and 7/20 as answers for #2, there is no clear yes or no. Am I overlooking something on this one?
Math Expert
Joined: 02 Sep 2009
Posts: 53066

### Show Tags

11 Nov 2017, 00:28
zflodeen wrote:
I can certainly see the logic in the explanation with this question, but I answered E. My basis for E is that all the terms could be 1/5 in which case the median is 1/5. My understanding of the wording of the question is the median has to be less than 1/5 to give a hard yes, but if you can have 1/5 as well as 1/2 and 7/20 as answers for #2, there is no clear yes or no. Am I overlooking something on this one?

In a Yes/No Data Sufficiency questions, statement(s) is sufficient if the answer is “always yes” or “always no” while a statement(s) is insufficient if the answer is "sometimes yes" and "sometimes no".

The question asks: is the median of the list less than 1/5?

From (2) the median could be 1/2, 1/5 or 7/20. None of the possible values is less than 1/5. So, we have a definite NO answer to the question for all three possible values of the median. Sufficient.

Hope it's clear.
_________________
Intern
Joined: 04 Sep 2017
Posts: 22
Location: United States
Concentration: Finance
GMAT 1: 610 Q36 V36
GMAT 2: 680 Q40 V36
GPA: 3.3
WE: Consulting (Mutual Funds and Brokerage)

### Show Tags

11 Nov 2017, 09:12
Thank you Bunuel! That helps to clear up my thinking. I had a lapse in my brain and forgot that 1/2 is greater than 1/5. Thanks again!
Manager
Joined: 25 Jan 2018
Posts: 95
Location: United States (IL)
Concentration: Strategy, Operations
WE: Business Development (Other)

### Show Tags

10 Apr 2018, 11:19
Hello Bunuel -

As per choice B - "The product of any two term of the list is terminating decimal".
now the list is of 10 numbers and consists of 1/2 and 1/5. So any two term can be 1/2 and 1/2 also right ???. I was confused about this while answering.
Shouldn't the choice be - "The product of any two distinct term of the list is terminating decimal".

Kindly explain so that I can clear my concept.
Math Expert
Joined: 02 Sep 2009
Posts: 53066

### Show Tags

10 Apr 2018, 11:38
Hello Bunuel -

As per choice B - "The product of any two term of the list is terminating decimal".
now the list is of 10 numbers and consists of 1/2 and 1/5. So any two term can be 1/2 and 1/2 also right ???. I was confused about this while answering.
Shouldn't the choice be - "The product of any two distinct term of the list is terminating decimal".

Kindly explain so that I can clear my concept.

Why were you confused? Yes, the two terms could be 1/2 and 1/2. Why not? 1/2*1/2 = 1/4 = terminating decimal.
_________________
Manager
Joined: 25 Jan 2018
Posts: 95
Location: United States (IL)
Concentration: Strategy, Operations
WE: Business Development (Other)

### Show Tags

10 Apr 2018, 12:36
My Bad - to get a terminating decimal - the denominator needs to be in the form of 2(power -n) * 5 (power - n) . N can always be 0 as well. Time pressure - I am sorry.
Intern
Joined: 16 Oct 2017
Posts: 5
Location: India
Schools: CBS '21
GMAT 1: 680 Q47 V40
GPA: 3.67

### Show Tags

01 May 2018, 18:38
I think this is a high-quality question and I agree with explanation. The Statement (2) is sufficient but the reason for sufficiency needs to be explained better because 1/8,1/10,1/4 and so on can also be in the set. But median or any of these values will continue to be lesser than 1/5. So the main reason we chose 1/2 & 1/5 is because they have the highest value that gives terminating decimals when multiplied.

PS: Give me kudos if you see fit
Math Expert
Joined: 02 Sep 2009
Posts: 53066

### Show Tags

01 May 2018, 19:58
kittyman wrote:
I think this is a high-quality question and I agree with explanation. The Statement (2) is sufficient but the reason for sufficiency needs to be explained better because 1/8,1/10,1/4 and so on can also be in the set. But median or any of these values will continue to be lesser than 1/5. So the main reason we chose 1/2 & 1/5 is because they have the highest value that gives terminating decimals when multiplied.

PS: Give me kudos if you see fit

That's not correct. 1/8, 1/10 and 1/4 cannot be in the set because we are told that the set consists of 10 terms, each of which is a reciprocal of a prime number. 8, 10 and 4 are not primes.
_________________
Intern
Joined: 16 Oct 2017
Posts: 5
Location: India
Schools: CBS '21
GMAT 1: 680 Q47 V40
GPA: 3.67

### Show Tags

02 May 2018, 02:43
Bunuel wrote:
kittyman wrote:
I think this is a high-quality question and I agree with explanation. The Statement (2) is sufficient but the reason for sufficiency needs to be explained better because 1/8,1/10,1/4 and so on can also be in the set. But median or any of these values will continue to be lesser than 1/5. So the main reason we chose 1/2 & 1/5 is because they have the highest value that gives terminating decimals when multiplied.

PS: Give me kudos if you see fit

That's not correct. 1/8, 1/10 and 1/4 cannot be in the set because we are told that the set consists of 10 terms, each of which is a reciprocal of a prime number. 8, 10 and 4 are not primes.

Understood Thanks

Sent from my Moto G (4) using GMAT Club Forum mobile app
Intern
Joined: 25 Oct 2017
Posts: 2

### Show Tags

20 Jun 2018, 06:09
I think this is a high-quality question and I agree with explanation.
Manager
Joined: 25 May 2016
Posts: 84
Location: Singapore
Concentration: Finance, General Management
GMAT 1: 620 Q46 V30

### Show Tags

04 Jul 2018, 19:09
Why only 1/2 and 1/5 for statement two? It can also be 1/3, 1/7, 1/11 etc., right?
_________________

1 Kudos left to unlock next level. Help me by Contributing one for cause .. Please

Manick9

If you found my post helpful, kindly press "+1 Kudos" to appreciate

Math Expert
Joined: 02 Sep 2009
Posts: 53066

### Show Tags

04 Jul 2018, 19:17
1
Manick9 wrote:
Why only 1/2 and 1/5 for statement two? It can also be 1/3, 1/7, 1/11 etc., right?

No. If there are reciprocals of other primes than 2 and 5, then the product of ANY two terms of the list won't be a terminating decimal. For example, if the list is {1/2, 1/2, 1/2, 1/2, 1/2, 1/2, 1/5, 1/5, 1/5, 1/3}, then no pair with 1/3 will produce the product which is a terminating decimal: 1/2*1/3 = 1/6 = 0.1666666.... and 1/5*1/6 = 0.0333333............... (reduced fraction to be terminating its denominator must have only 2's and/or 5 in it).
_________________
Manager
Joined: 25 May 2016
Posts: 84
Location: Singapore
Concentration: Finance, General Management
GMAT 1: 620 Q46 V30

### Show Tags

04 Jul 2018, 19:32
Thanks Bunuel!
I didn't understand the definition of terminating decimal clearly at first. I got it confused with recurring decimal.
_________________

1 Kudos left to unlock next level. Help me by Contributing one for cause .. Please

Manick9

If you found my post helpful, kindly press "+1 Kudos" to appreciate

Intern
Joined: 15 Jul 2018
Posts: 11

### Show Tags

31 Oct 2018, 09:58
Please what is a terminating decimal?
Manager
Joined: 09 Jun 2014
Posts: 238
Location: India
Concentration: General Management, Operations
Schools: Tuck '19

### Show Tags

31 Oct 2018, 21:35
I think this is a high-quality question. Loved this questions!!
Math Expert
Joined: 02 Sep 2009
Posts: 53066

### Show Tags

31 Oct 2018, 21:47
Re: D01-23   [#permalink] 31 Oct 2018, 21:47

Go to page   Previous    1   2   [ 38 posts ]

Display posts from previous: Sort by

# D01-23

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

Moderators: chetan2u, Bunuel

 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®.