GRE Prep 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.
Sep 28Live Online Class with Top GRE Expert Mike Butville
08:00 PM EDT
-10:00 PM EDT
Top scores are possible when you enroll in a powerful GRE course, taught live online + 6 months access to TTP GRE OnDemand video courses included! Class starts Mon/Wed Sept. 28, 2026 - Dec. 9, 2026, 8:00pm-10:00pm EST
A bag has 20 marbles that are either black or white.
[#permalink]
25 Dec 2018, 15:14
25 Dec 2018, 15:14
2
Expert Reply
2
Bookmarks
00:00
Question Stats:
82% (01:08) correct
17% (00:45) wrong based on 133 sessions
Hide Show timer Statistics
A bag has 20 marbles that are either black or white.
Quantity A |
Quantity B |
The number of times one must randomly draw a marble from the bag, without replacing it, to ensure that at least 4 black marbles are selected |
The number of times one must randomly draw a marble from the bag, without replacing it, to ensure that at least 4 white marbles are selected |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Re: A bag has 20 marbles that are either black or white.
[#permalink]
26 Dec 2018, 13:12
26 Dec 2018, 13:12
2
Answer: D
20 marbles: black or white
A: The number of times one must randomly draw a marble from the bag, without replacing it, to ensure that at least 4 black marbles are selected
B: The number of times one must randomly draw a marble from the bag, without replacing it, to ensure that at least 4 white marbles are selected
Since we don’t have any information about the number of black or white ones, we can't decide which one is more or less, therefore, we can't construe about their probabilities. hence, the answer is D.
20 marbles: black or white
A: The number of times one must randomly draw a marble from the bag, without replacing it, to ensure that at least 4 black marbles are selected
B: The number of times one must randomly draw a marble from the bag, without replacing it, to ensure that at least 4 white marbles are selected
Since we don’t have any information about the number of black or white ones, we can't decide which one is more or less, therefore, we can't construe about their probabilities. hence, the answer is D.
Re: A bag has 20 marbles that are either black or white.
[#permalink]
27 Dec 2018, 00:25
27 Dec 2018, 00:25
2
Expert Reply
Carcass wrote:
A bag has 20 marbles that are either black or white.
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
The number of times one must randomly draw a marble from the bag, without replacing it, to ensure that at least 4 black marbles are selected |
The number of times one must randomly draw a marble from the bag, without replacing it, to ensure that at least 4 white marbles are selected |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Our answer will be the marbles which are lesser than the other.
Say there are 5 black and 15 whites..
We can be sure that 4 whites are there if we pick 5+4=9 and that 4 blacks are there if we pick 15+4=19..
But we are not aware of the number of black or white marbles.
Thus D
