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

 It is currently 09 Dec 2019, 17:09

### 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

# M13-23

Author Message
TAGS:

### Hide Tags

Manager
Joined: 17 May 2017
Posts: 119
Schools: ESSEC '20
GPA: 3

### Show Tags

11 Sep 2017, 23:11
1
still confused if we take x= 5 then a can be both positive and negative so how is the first statement sufficient?
Manager
Joined: 01 Sep 2016
Posts: 185
GMAT 1: 690 Q49 V35

### Show Tags

17 Sep 2017, 04:56
Bunuel : Can you help me with a simple question:

Why haven't you used discriminant method to solve Option B as well. If you solve it using D method, you will get A>0, what am I missing here please?
_________________
we shall fight on the beaches,
we shall fight on the landing grounds,
we shall fight in the fields and in the streets,
we shall fight in the hills;
we shall never surrender!
Intern
Joined: 10 Mar 2017
Posts: 4
GMAT 1: 660 Q49 V32

### Show Tags

22 Sep 2017, 23:17
1
I think this is a high-quality question and I agree with explanation. Hi Bunuel,
Is the following approach for statement-1 wrong?
x^2-2x+a is positive for all values of x,
Hence it should hold its ground even when x=0.
So, when x=0,
x^2-2x+a is reduced to a
Hence a has to be greater than 0.
Manager
Joined: 26 Dec 2017
Posts: 148

### Show Tags

13 Jan 2018, 04:44
4
1
Hi Bunnel ,

I too have same doubt that why imaginary roots discriminant method is not used in S2 if used you will get a>0 but also actually it is not true as a=0 also satisfies the equation which is the reason for insufficiency.

So m main doubt is Can I know whether discriminant method is suffice(S1) or not (S2) for checking whether statements suffice or not
Intern
Joined: 02 Feb 2018
Posts: 31

### Show Tags

01 Dec 2018, 08:53
Addition to (2): A can also be negative when x =0
Senior Manager
Joined: 03 Sep 2018
Posts: 252
Location: Netherlands
GMAT 1: 710 Q48 V40
GMAT 2: 780 Q50 V49
GMAT 3: 760 Q49 V44
GPA: 4

### Show Tags

01 Nov 2019, 04:38
I am wondering whether we can do the following.

$$x^2-2x+a>0 \implies a>x(2-x) \implies a>0$$ OR $$a>2$$

Is that legal Bunuel?
_________________
Good luck to you.
Re: M13-23   [#permalink] 01 Nov 2019, 04:38

Go to page   Previous    1   2   [ 26 posts ]

Display posts from previous: Sort by

# M13-23

Moderators: chetan2u, Bunuel