Last visit was: 21 Nov 2024, 17:53 It is currently 21 Nov 2024, 17:53
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

Close

GRE Prep 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 GRE 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.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel
PREVIOUS TOPIC
NEXT TOPIC

Set consists of the positive multiples of 5

Tags :
Find Similar Topics  About  Add a Tag

Show Tags
Hide Tags

avatar
yasir9909
Manager
Manager
Joined: 13 Aug 2016
Posts: 77
Own Kudos [?]: 150 [5]
Given Kudos: 0
GRE 1: Q158 V154
Send PM
Set consists of the positive multiples of 5 [#permalink] New post   Updated on: 29 Aug 2016, 02:16
1
4
Bookmarks
00:00

Question Stats:

38% (02:41) correct 61% (02:47) wrong based on 31 sessions

Hide Show timer Statistics

Set X consists of the positive multiples of 5 and set Y consists of odd prime numbers less than 20.If set Z consists of every distinct integer less than 100 that is the product of one element from set X and one element from set Y,then set Z consists of how many elements?

    A). 12
    B). 14
    C). 15
    D). 16
    E). 18
ShowHide Answer
Official Answer
B

Originally posted by yasir9909 on 27 Aug 2016, 07:04.
Last edited by Carcass on 29 Aug 2016, 02:16, edited 2 times in total.
Edited by Carcass
avatar
Sonalika42
Manager
Manager
Joined: 12 Jan 2016
Posts: 142
Own Kudos [?]: 187 [0]
Given Kudos: 0
Send PM
Re: Set consists of the positive multiples of 5 [#permalink] New post   27 Aug 2016, 09:02
I think answer should be C
Set Q--->5,10,15,20,25,30
Set Y--->3,5,7,11,13,17,19
set Z--->5 multiplying it with all the numbers in set Y--->7
10 multiplying it with 3, 7, 5 in set Y--->3
15 multiplying it with 3,5 in set Y-->2
20 multiplying it with 3 in set Y --->1
25 multiplying it with 3 in set Y --->1
30 multiplying it with with 3 in set Y --->1
avatar
yasir9909
Manager
Manager
Joined: 13 Aug 2016
Posts: 77
Own Kudos [?]: 150 [0]
Given Kudos: 0
GRE 1: Q158 V154
Send PM
Re: Set consists of the positive multiples of 5 [#permalink] New post   28 Aug 2016, 02:10
@Sonalika42

I also think answer should be C but I am not able to asses why it is given to be B in 1007 Practice Questions by Princeton Review.

I have edited the post because Q stands for Question while it was Set X so you also replace Q with X in your post
avatar
yasir9909
Manager
Manager
Joined: 13 Aug 2016
Posts: 77
Own Kudos [?]: 150 [0]
Given Kudos: 0
GRE 1: Q158 V154
Send PM
Re: Set consists of the positive multiples of 5 [#permalink] New post   Updated on: 28 Aug 2016, 02:52
1
@Sonalika42

Here is my solution to this question:

Set X = {5,10,15,20,25,30,35,...}
Set Y = {3,5,7,11,13,17,19}
Set Z = {3*5,3*10,3*15,3*20,3*25,3*30,
5*5,5*10,5*15,
7*5,7*10,
11*5,
13*5,
17*5,
19*5}
Z = {15,30,45,60,75,90,25,50,75,35,70,55,65,85,95}

It seems like as 75 is repeated so it is counted as one element in set Z.

=> Thus Set Z has 14 elements instead of 15.This could be the only justification for answer to be 14 i.e. (B)

Originally posted by yasir9909 on 28 Aug 2016, 02:21.
Last edited by yasir9909 on 28 Aug 2016, 02:52, edited 1 time in total.
avatar
yasir9909
Manager
Manager
Joined: 13 Aug 2016
Posts: 77
Own Kudos [?]: 150 [0]
Given Kudos: 0
GRE 1: Q158 V154
Send PM
Re: Set consists of the positive multiples of 5 [#permalink] New post   28 Aug 2016, 02:47
My perception about repetition of elements in a set is right.This is what mentioned on sets on page 138,under caption Sets,Lits and Sequences in Official Guide of GRE,2nd Edition by ETS:

"When the elements of a set are given,repetitions are not counted as additional elements and the order of the elements is not relevant.Elements are also called members"

So this proves that 75 which is repeated in Set Z would be counted as one element instead of counting it twice.

Difficult questions on actual GRE Exam pose such subtle conceptual twists that make the test taker commit mistake and lose points on GRE

regards
m.yasir
avatar
Sonalika42
Manager
Manager
Joined: 12 Jan 2016
Posts: 142
Own Kudos [?]: 187 [0]
Given Kudos: 0
Send PM
Re: Set consists of the positive multiples of 5 [#permalink] New post   28 Aug 2016, 03:08
@Yasir

Oops my wrong...... you are right it should be 14 i mistakenly repeated 75.
User avatar
G
motion2020
Retired Moderator
Joined: 19 Nov 2020
Posts: 326
Own Kudos [?]: 373 [1]
Given Kudos: 64
GRE 1: Q160 V152
Send PM
Set consists of the positive multiples of 5 [#permalink] New post   30 Jul 2021, 10:48
1
yasir9909 wrote:
Set X consists of the positive multiples of 5 and set Y consists of odd prime numbers less than 20.If set Z consists of every distinct integer less than 100 that is the product of one element from set X and one element from set Y,then set Z consists of how many elements?

    A). 12
    B). 14
    C). 15
    D). 16
    E). 18

Set X = {5*(1+2+3...20 ... n); n positive multiples}
Set Y = {3, 5, 7, 11, 13, 17, 19}
There are
5*1 times 7 primes = 7 elements {15, 25, 35, 55, 65, 85, 95}
5*2 times 3 primes = 3 elements {30, 50, 70}
5*3 times 2 primes = 2 elements {45, 75}
5*4 times 1 prime = 1 element {60}
5*5 times 1 prime = 1 element {75} <---- repeated with 5*3 times 2 primes, exclude since elements are distinct in set Z
5*6 times 1 prime = 1 element {90}
In total 15-1 OR 14 elements in set Z. Answer is B.

fixed.
avatar
G
XavierAlexander
Manager
Manager
Joined: 10 Dec 2020
Posts: 50
Own Kudos [?]: 87 [1]
Given Kudos: 955
GRE 1: Q166 V162
Send PM
Re: Set consists of the positive multiples of 5 [#permalink] New post   24 Dec 2021, 02:11
1
This question is NOT from any official GRE sources. It is from Princeton [ref.] [ref-2].
Kindly remove the deceptive tag - "Source: OG Big Book".
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 30003
Own Kudos [?]: 36341 [1]
Given Kudos: 25927
Send PM
Re: Set consists of the positive multiples of 5 [#permalink] New post   24 Dec 2021, 02:42
1
Expert Reply
XavierAlexander wrote:
This question is NOT from any official GRE sources. It is from Princeton [ref.] [ref-2].
Kindly remove the deceptive tag - "Source: OG Big Book".


Thank you. Fixed
Prep Club for GRE Bot
gmatclubot
Re: Set consists of the positive multiples of 5 [#permalink]
24 Dec 2021, 02:42
Moderators:
adewale223
GRE Instructor
84 posts
bronaugust
GRE Forum Moderator
37 posts
BrushMyQuant
Moderator
1111 posts
VibhuAnurag
GRE Instructor
234 posts

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

Main navigation

Partners

GRE Resources

www.ets.org/gre | About | Terms and Conditions and Privacy Policy | Prep Club for GRE Rules | Contact