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.
In box A, there are 10 red marbles, 10 green marbles and 10 yellow mar
[#permalink]
24 Feb 2022, 06:41
24 Feb 2022, 06:41
Expert Reply
00:00
Question Stats:
25% (03:34) correct
75% (02:43) wrong based on 4 sessions
Hide Show timer Statistics
In box A, there are 10 red marbles, 10 green marbles and 10 yellow marbles. Jack takes turn in picking randomly a marble from that box. What is the probability that Jack picks 4 marbles that have the same color?
A. 2/87
B. 16/29
C. 2/261
D. 28/1131
E. 28/3393
A. 2/87
B. 16/29
C. 2/261
D. 28/1131
E. 28/3393
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: In box A, there are 10 red marbles, 10 green marbles and 10 yellow mar
[#permalink]
24 Feb 2022, 06:52
24 Feb 2022, 06:52
Carcass wrote:
In box A, there are 10 red marbles, 10 green marbles and 10 yellow marbles. Jack takes turn in picking randomly a marble from that box. What is the probability that Jack picks 4 marbles that have the same color?
A. 2/87
B. 16/29
C. 2/261
D. 28/1131
E. 28/3393
A. 2/87
B. 16/29
C. 2/261
D. 28/1131
E. 28/3393
P(4 matching marbles) = P(1st is ANY color AND 2nd marble matches 1st AND 3rd marble matches 1st AND 4th marble matches 1st)
= P(1st is ANY color) x P(2nd marble matches 1st) x P(3rd marble matches 1st) x P(4th marble matches 1st)
= 30/30 x 9/29 x 8/28 x 7/27
= 1 x 9/29 x 2/7 x 7/27
= (9)(2)(7)/(29)(7)(27)
= (9)(2)/(29)(27)
= (1)(2)/(29)(3)
= 2/87
Answer: A
gmatclubot
Re: In box A, there are 10 red marbles, 10 green marbles and 10 yellow mar [#permalink]
24 Feb 2022, 06:52
Moderators:
