If 3x < 2y < 0, which of the following must be the greatest?
a. 2y - 3x
b. 3x - 2y
c. -(3x - 2y)
d. -(3x + 2y)
e. 0
OA given: D
I was thinking if x and y are assumed to be -0.1 then D can't be true. And that means answer should be E in all cases.
Am I missing something?
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
Problem Solving - Beatthegmat practice question
This topic has expert replies
-
beat_gmat_09
- Master | Next Rank: 500 Posts
- Posts: 437
- Joined: Sat Nov 22, 2008 5:06 am
- Location: India
- Thanked: 50 times
- Followed by:1 members
- GMAT Score:580
x and y both are negative. Pick x =-2, y=-1kuiper wrote:If 3x < 2y < 0, which of the following must be the greatest?
a. 2y - 3x
b. 3x - 2y
c. -(3x - 2y)
d. -(3x + 2y)
e. 0
OA given: D
I was thinking if x and y are assumed to be -0.1 then D can't be true. And that means answer should be E in all cases.
Am I missing something?
a. 2(-1)-3(-2) = -2+6=4
b. 3(-2)-2(-1)= -6+2 = -4
c. -(3(-2)-2(-1)) = -(-6+2)=-(-4)=4
d. -(3(-2)+2(-1))=-(-6-2)=-(-8) = 8
e. 0
8 is greatest, hence D
Hope is the dream of a man awake
-
beat_gmat_09
- Master | Next Rank: 500 Posts
- Posts: 437
- Joined: Sat Nov 22, 2008 5:06 am
- Location: India
- Thanked: 50 times
- Followed by:1 members
- GMAT Score:580
If x and y both are -0.1 then
D. -(3*(-0.1) + 2*(-0.1)) = -(-0.3-0.2) = -(-0.5) = +0.5 > 0
D. -(3*(-0.1) + 2*(-0.1)) = -(-0.3-0.2) = -(-0.5) = +0.5 > 0
Hope is the dream of a man awake
GMAT/MBA Expert
-
Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7245
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
We notice that -(3x - 2y) = -3x + 2y = 2y - 3x; i.e. the expression in answer choice A is equivalent to the expression in answer choice C. Therefore, neither A nor C can be the correct answer, and we eliminate both.kuiper wrote:If 3x < 2y < 0, which of the following must be the greatest?
a. 2y - 3x
b. 3x - 2y
c. -(3x - 2y)
d. -(3x + 2y)
e. 0
OA given: D
Next, notice that 3x - 2y is negative (since 3x < 2y); therefore, B cannot be the correct answer, either (because it is less than 0, which is answer choice E).
We need to decide between D and E. Notice that both 3x and 2y are strictly less than zero, and so is their sum. Since 3x + 2y is strictly less than zero, -(3x + 2y) is strictly greater than zero; which means D is the greatest.
Alternate Solution:
We can let x = -3 and y = -2 and check each answer choice.
Choice A: 2y - 3x = -4 - (-9) = 5
Choice B: 3x - 2y = -9 - (-4) = -5. Eliminate B.
Choice C: -(3x - 2y) = -(-5) = 5 (This is Choice B, with the sign reversed.) Because this is equal to Choice A, we can eliminate both A and C.
Choice D: -(3x + 2y) = -(-9 + (-4)) = -(-13) = 13. We compare this to Choice E and see that 13 is greater than 0. Choice D is the correct answer.
Answer: D
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
