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.
Nov 2007:30 AM PST
-08:30 AM PST
Learn what truly sets the UC Riverside MBA apart and how it helps in your professional growth
Nov 2211:00 AM IST
-01:00 PM IST
Do RC/MSR passages scare you? e-GMAT is conducting a masterclass to help you learn – Learn effective reading strategies Tackle difficult RC & MSR with confidence Excel in timed test environment- Nov 23
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. 
Nov 2510:00 AM EST
-11:00 AM EST
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors.
13 May 2020, 01:57
Kudos
Bookmarks
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
75%
(hard)
Question Stats:
50% (01:57) correct
50%
(01:37)
wrong
based on 228
sessions
History
Date
Time
Result
Not Attempted Yet
A bag contains r red, g green, and w white marbles, where r, g and w are all positive integers. If one marble is picked randomly, is the probability that the marble is red higher than the probability that the marble is either green or white?
(1) The probability of selecting a green marble is 4/9
(2) The total number of marbles in the bag is less than 15.
Are You Up For the Challenge: 700 Level Questions
(1) The probability of selecting a green marble is 4/9
(2) The total number of marbles in the bag is less than 15.
Are You Up For the Challenge: 700 Level Questions
13 May 2020, 03:06
Kudos
Bookmarks
Is r>g+w
Statement 1- Total= 9x and Green= 4x
Case 1 - G=4; W=1; Total =9 (NO)
Case 2 - G=12; W=1; Total= 27 (Yes)
Insufficient
Statement 2-
Case 1- R= 1; Total= 14 (NO)
Case 2- R= 8; Total= 14 (Yes)
Insufficient
Combining both statement
Since Total number of balls is a multiple of 9 and is less than 15, Total number of balls must be 9; hence, number of green balls = 4.
Number of white balls is greater than or equal to 1; hence 1 ≤ r ≤ 4 < g+w
Sufficient
Statement 1- Total= 9x and Green= 4x
Case 1 - G=4; W=1; Total =9 (NO)
Case 2 - G=12; W=1; Total= 27 (Yes)
Insufficient
Statement 2-
Case 1- R= 1; Total= 14 (NO)
Case 2- R= 8; Total= 14 (Yes)
Insufficient
Combining both statement
Since Total number of balls is a multiple of 9 and is less than 15, Total number of balls must be 9; hence, number of green balls = 4.
Number of white balls is greater than or equal to 1; hence 1 ≤ r ≤ 4 < g+w
Sufficient
Bunuel
13 May 2020, 05:54
Kudos
Bookmarks
Bunuel
Solution
Step 1: Analyse Question Stem
- • r, g, and w are positive integer.
• If one marble is picked randomly,
- o Probability that picked marble is red = \(\frac{r}{r + g + w}\)
o Probability that picked marble is either green or white = \(\frac{g}{r + g + w} + \frac{w}{r + g + w } = \frac{g+ w}{r + g + w}\)
- o Or, we need to find out if \(r > g + w\)
Step 2: Analyse Statements Independently (And eliminate options) – AD/BCE
Statement 1: The probability of selecting a green marble is 4/9
- • According to this statement, \(\frac{g}{r + g + w} = \frac{4}{9}\)
• From this statement, all we can know is that g is a positive multiple of 4 and r + g + w is a positive multiple of 9.
• However, we don’t know the exact value of r, g, and w. Therefore, we cannot say whether r > g + w or not.
Statement 2: The total number of marbles in the bag is less than 15.
- • \(r + g + w < 15\)
- o So, \(r + g + w\) can be \(3 ,4, 5, ……14.\)
- o Case 1: If \(r = 2 , g = 3,\) and \(w = 4\)
- In this case, \(r +g +w = 9 < 15\) and \(r < g + w\)
- In this case, \(r +g +w = 11< 15 \) and \(r > g + w\)
Step 3: Analyse Statements by combining.
- • From statement 1: g is a positive multiple of 4 and \(r + g+ w\) is a positive multiple of 9.
• From statement 2: r + g+ w < 15
• On combining the two statements we get,
- o \(r + g+ w = 9\) (only positive multiple of \(9 < 15\))
o and \(g = 4\) ( g cannot be 8 since in that case one of r and w has to zero)
- Therefore, \(r + w = 9 – g = 5\)
Now, minimum value of w can be 1
- • Maximum value of \(r = 4 < g + w = 5\)
• Thus, \(r < g + w\)
