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 are 12 pens and 5 pencils in box A. An object is picked at rando
[#permalink]
31 Jan 2022, 06:14
31 Jan 2022, 06:14
Expert Reply
1
Bookmarks
00:00
Question Stats:
100% (02:03) correct
0% (00:00) wrong based on 4 sessions
Hide Show timer Statistics
There are 12 pens and 5 pencils in box A. An object is picked at random from box A and moved to box B, in which there are already 4 pens and 5 pencils. If one object is then to be picked from box B, what is the probability that a pen will be picked?
A. \(\frac{8}{17}\)
B. \(\frac{80}{153}\)
C. \(\frac{9}{17}\)
D. \(\frac{12}{17}\)
E. \(\frac{14}{17}\)
A. \(\frac{8}{17}\)
B. \(\frac{80}{153}\)
C. \(\frac{9}{17}\)
D. \(\frac{12}{17}\)
E. \(\frac{14}{17}\)
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: There are 12 pens and 5 pencils in box A. An object is picked at rando
[#permalink]
31 Jan 2022, 06:24
31 Jan 2022, 06:24
Carcass wrote:
There are 12 pens and 5 pencils in box A. An object is picked at random from box A and moved to box B, in which there are already 4 pens and 5 pencils. If one object is then to be picked from box B, what is the probability that a pen will be picked?
A. \(\frac{8}{17}\)
B. \(\frac{80}{153}\)
C. \(\frac{9}{17}\)
D. \(\frac{12}{17}\)
E. \(\frac{14}{17}\)
A. \(\frac{8}{17}\)
B. \(\frac{80}{153}\)
C. \(\frac{9}{17}\)
D. \(\frac{12}{17}\)
E. \(\frac{14}{17}\)
P(pen from box B) = P(pen from A AND pen from B OR pencil from A AND pen from B)
= P(pen from A AND pen from B) + P(pencil from A AND pen from B)
= [P(pen from A) x P(pen from B)] + [P(pencil from A) x P(pen from B)]
= [12/17 x 5/10] + [5/17 x 4/10]
= 60/170 + 20/170
= 80/170
= 8/17
Answer: A
gmatclubot
Re: There are 12 pens and 5 pencils in box A. An object is picked at rando [#permalink]
31 Jan 2022, 06:24
Moderators:
