Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 04 May 2015, 10:49

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# DS: X^2+ BX+ C=0,---> R,S are solutions of the

Author Message
TAGS:
Manager
Joined: 08 Apr 2004
Posts: 137
Location: Corea
Followers: 1

Kudos [?]: 170 [0], given: 0

DS: X^2+ BX+ C=0,---> R,S are solutions of the [#permalink]  07 Sep 2004, 06:24
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
DS: X^2+ BX+ C=0,---> R,S are solutions of the equation.Is R* S>0?
1. B<0
2. C<0
Director
Joined: 20 Jul 2004
Posts: 593
Followers: 1

Kudos [?]: 48 [0], given: 0

B.

Since R and S are solutions of the equation, the equation can be written as x^2 - (R+S)x + RS = 0

In this case, B = -(R+S) and C = RS.
From II, C < 0 => RS < 0, Ans to the question: No.
Joined: 31 Dec 1969
Location: India
Concentration: General Management, Strategy
GMAT 1: 710 Q49 V0
GMAT 2: 740 Q40 V50
GMAT 3: 700 Q48 V38
GPA: 3.6
Followers: 0

Kudos [?]: 89 [0], given: 87116

For the roots to be real and distinct in a quadratic equation, the determinant b^2-4ac > o

here b = B
c=C
a = 1

so, w have B^2 - 4C > 0

Now, 1) B < 0. Doesn't matter as B^2 is always +ve. So we dont know if B^2- 4C will be +ve or not. So insufficient

2) C<0. Sufficient. The B^2 - 4C will be > than 0.

Hence B.
Director
Joined: 16 Jun 2004
Posts: 893
Followers: 2

Kudos [?]: 19 [0], given: 0

guest was me..sorry forgot to login earlier.
Manager
Joined: 02 Apr 2004
Posts: 224
Location: Utrecht
Followers: 1

Kudos [?]: 13 [0], given: 0

Great work guys!

I took C as answer, while now it is obvious for me as well that B is sufficient. We need to understand the value of C to answer the question.

Regards,

Alex
Similar topics Replies Last post
Similar
Topics:
5 In the equation x^2+bx+c=0, b and c are constants, and x is 1 06 Mar 2014, 20:26
43 If r and s are the roots of the equation x^2 + bx + c = 0 27 20 Oct 2012, 11:12
If equation x^2+bx+c=0 have two same roots, b=? (1) c=9 (2) 2 21 Jun 2008, 18:16
How many integers can let x^2+bx+c=0? B and c are constants. 2 18 Aug 2006, 22:33
x^2+bx+c=0 b,c are constant integers, how many pairs of 5 06 May 2006, 02:44
Display posts from previous: Sort by