Last visit was: 23 Apr 2024, 16:28 It is currently 23 Apr 2024, 16:28

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
Board of Directors
Joined: 01 Sep 2010
Posts: 4380
Own Kudos [?]: 32863 [8]
Given Kudos: 4453
Send PM
Board of Directors
Joined: 01 Sep 2010
Posts: 4380
Own Kudos [?]: 32863 [1]
Given Kudos: 4453
Send PM
Math Expert
Joined: 02 Sep 2009
Posts: 92883
Own Kudos [?]: 618586 [4]
Given Kudos: 81563
Send PM
Board of Directors
Joined: 01 Sep 2010
Posts: 4380
Own Kudos [?]: 32863 [1]
Given Kudos: 4453
Send PM
Re: How many of the numbers x, y, and z are positive if each of [#permalink]
1
Kudos
:( why sometimes I do not active my brain ..........

Thank you Bunuel
avatar
Intern
Intern
Joined: 08 Sep 2012
Posts: 8
Own Kudos [?]: 18 [1]
Given Kudos: 10
GMAT 1: 770 Q50 V45
WE:General Management (Non-Profit and Government)
Send PM
Re: How many of the numbers x, y, and z are positive if each of [#permalink]
1
Kudos
For (1) x+y+z=20
if x=y=10 and c=0 ? then c is not positive hence we are not sure if all three are positive. Isn't (1) insufficient then?
avatar
Manager
Manager
Joined: 02 Mar 2012
Posts: 201
Own Kudos [?]: 292 [0]
Given Kudos: 4
Schools: Schulich '16
Send PM
Re: How many of the numbers x, y, and z are positive if each of [#permalink]
take any 2 numbers x,y, or z

given y,x, and z<10

i am taking x and Y

max value of x and y can be 9.99 or 9.999999

given , x+y+z=20

x and y won't alone give 20 so z has to be +ve

So all 3 number are positive.

2) no info about z

So answer is A
Manager
Manager
Joined: 19 Dec 2020
Posts: 161
Own Kudos [?]: 39 [0]
Given Kudos: 316
Send PM
Re: How many of the numbers x, y, and z are positive if each of [#permalink]
carcass wrote:
How many of the numbers x, y, and z are positive if each of these numbers is less than 10?

(1) x + y + z = 20
(2) x + y = 14



Key is to remember that x,y,z each is <10.

(1) \(x + y + z = 20\)

If any of the number is -ve, then there's no way the sum can be=20. so, they all must be +Ve

(2) \(x + y = 14\)

this is also possible when x and y are both +Ve. so, we know at least 2 are positive. but what about z?

Not sufficient.
Intern
Intern
Joined: 18 Feb 2021
Posts: 22
Own Kudos [?]: 5 [0]
Given Kudos: 17
Location: India
GMAT 1: 720 Q49 V38 (Online)
GPA: 3.75
Send PM
Re: How many of the numbers x, y, and z are positive if each of [#permalink]
Statement A: x+y+z=20
The maximum value of these numbers can be 9. Assume x=y=9. Hence, z will have to be 2. There is no way we can exceed sum of two vaiables by 20 and then have a third number negative to bring the sum to 20. Hence all three have to be positive. Sufficient

Statement B: x+y=14
Case 1: x=8, y=6 Possible
Case 2: x=9 y=5 Possible
Hence x and y have to be positive. But what about z. Nothing mentioned about z. So insufficient

Hence option A
Manager
Manager
Joined: 06 Oct 2020
Posts: 137
Own Kudos [?]: 107 [0]
Given Kudos: 77
Location: India
Schools: ISB'22
Send PM
Re: How many of the numbers x, y, and z are positive if each of [#permalink]
The answer is A.

Though I selected D.

Stmt 1: x + y + z = 20

9.9 + 9.9 + 0.2 = 20. All three positive.

Stmt 2. x + y = 14. There is no information about z. But i kept assuming x + y + z = 20 and thought z would be 6.

I wish i stop making this silly mistakes
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 32628
Own Kudos [?]: 821 [0]
Given Kudos: 0
Send PM
Re: How many of the numbers x, y, and z are positive if each 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: How many of the numbers x, y, and z are positive if each of [#permalink]
Moderator:
Math Expert
92883 posts

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