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.
There is a total of 120 marbles in a box, each of which is r
[#permalink]
27 Aug 2020, 09:55
27 Aug 2020, 09:55
Expert Reply
1
Bookmarks
00:00
Question Stats:
97% (00:48) correct
2% (00:54) wrong based on 38 sessions
Hide Show timer Statistics
There is a total of 120 marbles in a box, each of which is red, green, blue, or white. If one marble is drawn from the box at random, the probability that it will be white is 1/4 and the probability that it will be green is 1/3. What is the probability that the marble will be either red or blue ?
(A) 1/6
(B) 1/4
(C) 2/7
(D) 1/3
(E) 5/12
(A) 1/6
(B) 1/4
(C) 2/7
(D) 1/3
(E) 5/12
Re: There is a total of 120 marbles in a box, each of which is r
[#permalink]
27 Aug 2020, 09:55
27 Aug 2020, 09:55
Expert Reply
Post A Detailed Correct Solution For The Above Questions And Get A Kudos.
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
For more theory and practice see our GRE - Math Book
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
For more theory and practice see our GRE - Math Book
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: There is a total of 120 marbles in a box, each of which is r
[#permalink]
27 Aug 2020, 10:32
27 Aug 2020, 10:32
Carcass wrote:
There is a total of 120 marbles in a box, each of which is red, green, blue, or white. If one marble is drawn from the box at random, the probability that it will be white is 1/4 and the probability that it will be green is 1/3. What is the probability that the marble will be either red or blue ?
(A) 1/6
(B) 1/4
(C) 2/7
(D) 1/3
(E) 5/12
(A) 1/6
(B) 1/4
(C) 2/7
(D) 1/3
(E) 5/12
...the probability that it [the marble] will be white is 1/4
So, 1/4 of the 120 marbles are white.
In other words, there are 30 white marbles.
...the probability that it [the marble] will be green is 1/3
So, 1/3 of the 120 marbles are green .
In other words, there are 40 green marbles.
Altogether, there are 70 marbles that are EITHER white or green.
This means that the remaining 50 marbles are EITHER red or blue.
So, P(selected marble is EITHER red or blue) = 50/120
= 5/12
Answer: E
Cheers,
Brent
