For integers x and y, x²y>>0. Which of the following must be true?
I. xy > 0
II. x > 0
III. y > 0
A. I only
B. II only
C. III only
D. II and III only
E. I, II, and III
Answer: C
Source: Veritas Prep
For integers x and y, x²y>>0. Which of the following must be true?
This topic has expert replies
-
- Legendary Member
- Posts: 1223
- Joined: Sat Feb 15, 2020 2:23 pm
- Followed by:1 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
As we know, \(x\) can be positive or negative, the only required condition to satisfy the inequality is that \(y > 0\).BTGModeratorVI wrote: ↑Fri Apr 03, 2020 9:40 amFor integers x and y, x²y>>0. Which of the following must be true?
I. xy > 0
II. x > 0
III. y > 0
A. I only
B. II only
C. III only
D. II and III only
E. I, II, and III
Answer: C
Source: Veritas Prep
Hence, C
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
One approach is to TEST some x and y values that satisfy the given condition that x²y > 0BTGModeratorVI wrote: ↑Fri Apr 03, 2020 9:40 amFor integers x and y, x²y>>0. Which of the following must be true?
I. xy > 0
II. x > 0
III. y > 0
A. I only
B. II only
C. III only
D. II and III only
E. I, II, and III
Answer: C
Source: Veritas Prep
For example x = -1 and y = 1 satisfies the inequality x²y > 0
Now let's use these values to check our 3 statements:
I. xy > 0. Plug in our values to get: (-1)(1) = -1. This means xy is NOT greater than 1. The question asks, "Which of the following must be true?"
So statement I is NEED NOT be true.
This means we can ELIMINATE answer choices A and E
II. x > 0. Plug in x-value to get: -1 > 0
This is NOT true.
This means we can ELIMINATE answer choices B and D
This leaves us with answer choice C only, which means statement III MUST be true
Answer: C
Cheers,
Brent
GMAT/MBA Expert
- Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7249
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
Since x^2 is always positive, y must be positive as well. So III is true. However, x could be either positive or negative. If x is negative, neither I nor II would be true.BTGModeratorVI wrote: ↑Fri Apr 03, 2020 9:40 amFor integers x and y, x²y>>0. Which of the following must be true?
I. xy > 0
II. x > 0
III. y > 0
A. I only
B. II only
C. III only
D. II and III only
E. I, II, and III
Answer: C
Source: Veritas Prep
Answer: C
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews