Forum Home > GMAT > Quantitative > Problem Solving (PS)
Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Dec 1310:00 AM EST
-12:00 PM EST
Have you ever wondered how to score a PERFECT 805 on the GMAT? Meet Julia, a banking professional who used the Target Test Prep course to achieve this incredible feat. Julia's story is nothing short of an inspiration.
Dec 1410:00 AM EST
-12:00 PM EST
Think a 100% GMAT Verbal score is out of your reach? Target Test Prep will make you think again! Our course uses techniques such as topical study and spaced repetition to maximize knowledge retention and make studying simple and fun.
Dec 1411:00 AM IST
-01:00 PM IST
Attend this session to learn how to Deconstruct arguments, Pre-Think Author’s Assumptions, and apply Negation Test.- Dec 15
11:00 AM IST
-01:00 PM IST
Attend this free GMAT Algebra Webinar and learn how to master the most challenging Inequalities and Absolute Value problems with ease. 
Dec 1608:00 AM PST
-11:59 PM PST
GMAT Club 12 Days of Christmas is a 4th Annual GMAT Club Winter Competition based on solving questions. This is the Winter GMAT competition on GMAT Club with an amazing opportunity to win over $40,000 worth of prizes!
09 Dec 2019, 01:13
Kudos
Bookmarks
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
95%
(hard)
Question Stats:
31% (01:54) correct
69%
(01:58)
wrong
based on 152
sessions
History
Date
Time
Result
Not Attempted Yet
In the equation \(x^2 + bx + 7= 0\), where x is a variable, and b is a constant. What is the value of b?
(1) x can take only positive integer values
(2) b is a negative integer
Are You Up For the Challenge: 700 Level Questions
(1) x can take only positive integer values
(2) b is a negative integer
Are You Up For the Challenge: 700 Level Questions
Updated on: 04 Aug 2020, 19:41
Originally posted by TestPrepUnlimited on 09 Dec 2019, 09:46.
Last edited by TestPrepUnlimited on 04 Aug 2020, 19:41, edited 1 time in total.
Last edited by TestPrepUnlimited on 04 Aug 2020, 19:41, edited 1 time in total.
Kudos
Bookmarks
Bunuel
In the equation \(x^2 + bx + 7= 0\), where x is a variable, and b is a constant. What is the value of b?
(1) x can take only positive integer values
(2) b is a negative integer
Are You Up For the Challenge: 700 Level Questions
(1) x can take only positive integer values
(2) b is a negative integer
Are You Up For the Challenge: 700 Level Questions
Analyzing the Question:
If we have an equation in the form \(x^2 + ax + b= 0\), a is the negative sum of the two roots and b is the product of the two roots. So for \(x^2 + bx + 7= 0\) if we declare the two roots and m and n we have \(m*n = 7\) and \(m + n = -b\).
Statement 1:
m and n are positive and must be integers as x can only take integer values. Due to knowing \(m*n = 7\), we can only have m = 1, n = 7 or m = 7, n = 1. Thus either way we have \(b = -(m+n) = -8\)
Statement 2:
b can be any negative integer. Although the equation might not have solutions for a particular range of b, that is not an issue as we're asking for b. Insufficient.
Ans: A
09 Dec 2019, 13:31
Kudos
Bookmarks
TestPrepUnlimited
Bunuel
In the equation \(x^2 + bx + 7= 0\), where x is a variable, and b is a constant. What is the value of b?
(1) x can take only positive integer values
(2) b is a negative integer
Are You Up For the Challenge: 700 Level Questions
(1) x can take only positive integer values
(2) b is a negative integer
Are You Up For the Challenge: 700 Level Questions
Analyzing the Question:
If we have an equation in the form \(x^2 + ax + b= 0\), a is the negative sum of the two roots and b is the product of the two roots. So for \(x^2 + bx + 7= 0\) if we declare the two roots and m and n we have \(m*n = 7\) and \(m + n = -b\).
Statement 1:
m and n are positive, therefore -b must be positive and b must be negative. Insufficient.
Statement 2:
Insufficient.
Combined:
We have duplicate information, we can automatically choose E. Besides m = 1 and n = 7 we can also have m = 0.5, n = 14, or m = n = sqrt(7) etc so there are multiple values of b we can take.
