Last visit was: 13 Nov 2024, 19:23 It is currently 13 Nov 2024, 19:23
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

Close

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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel
PREVIOUS TOPIC
NEXT TOPIC

If the probabilities of Hank and Babe, two baseball players in the sam

Tags :
Find Similar Topics  About  Add a Tag

Show Tags
Hide Tags

User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 29955
Own Kudos [?]: 36212 [1]
Given Kudos: 25903
Send PM
If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   19 Apr 2022, 01:00
Expert Reply
1
Bookmarks
00:00

Question Stats:

80% (00:46) correct 20% (00:40) wrong based on 10 sessions

Hide Show timer Statistics

If the probability of Hank and Babe, two baseball players in the same MLB team, of hitting a home run in today's game is 0.3 and 0.2, respectively, what is the probability that at least one of them will hit a home run in today's game?

Show: ::
0.44


Most Helpful Community Reply
User avatar
P
GreenlightTestPrep
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12188 [2]
Given Kudos: 136
Send PM

Top Member of the Month
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   23 May 2022, 06:21
2
Carcass wrote:
If the probability of Hank and Babe, two baseball players in the same MLB team, of hitting a home run in today's game is 0.3 and 0.2, respectively, what is the probability that at least one of them will hit a home run in today's game?

Show: ::
0.44


Given:
P(Hank hits home run) = 0.3, which means P(Hank does NOT hit home run) = 1 - 0.3 = 0.7
P(Babe hits home run) = 0.2, which means P(Babe does NOT hit home run) = 1 - 0.2 = 0.8

When it comes to probability questions involving "at least," it's best to try using the complement.
That is, P(Event A happening) = 1 - P(Event A not happening)
So, here we get: P(at least 1 home run) = 1 - P(not getting at least 1 home run)
So, we can write: P(getting at least 1 home run) = 1 - P(getting zero home runs)

P(getting zero home runs)
P(getting zero home runs) = (Hank does not get a home run AND Babe does not get a home run)
= (Hank does not get a home run) x P(Babe does not get a home run)
= 0.7 x 0.8
= 0.56

So, P(getting at least 1 home run) = 1 - 0.56 = 0.44
General Discussion
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 29955
Own Kudos [?]: 36212 [0]
Given Kudos: 25903
Send PM
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   27 Apr 2022, 22:13
Expert Reply
Image



Replying to the question in 48 Hours

avatar
krpajedrez
Intern
Intern
Joined: 10 May 2022
Posts: 9
Own Kudos [?]: 12 [0]
Given Kudos: 1
Send PM
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   23 May 2022, 00:35
Are you sure the answer is 0.6 and not 0.44 ?

P( at least 1 will hit ) = 1 - P ( none will hit )

And, P ( none will hit ) = P( A won't hit) * P (B won't hit)
= (1 - 0.3 ) * ( 1- 0.2)
= 0.7 * 0.8
= 0.56

Thus, P ( at least 1 will hit) = 1 - 0.56 = 0.44.
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 29955
Own Kudos [?]: 36212 [0]
Given Kudos: 25903
Send PM
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   23 May 2022, 03:26
Expert Reply
OE

Quote:
This is a simultaneous/independent probability problem in that Hank and Babe's batting performances do not influence each others'. The probability that at least one player will hit a home run in today's game is (0.3)(0.2) = 0.6.
avatar
krpajedrez
Intern
Intern
Joined: 10 May 2022
Posts: 9
Own Kudos [?]: 12 [1]
Given Kudos: 1
Send PM
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   23 May 2022, 03:38
1
Carcass wrote:
OE

Quote:
This is a simultaneous/independent probability problem in that Hank and Babe's batting performances do not influence each others'. The probability that at least one player will hit a home run in today's game is (0.3)(0.2) = 0.6.


But, 0.3*0.2 = 0.06
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 29955
Own Kudos [?]: 36212 [0]
Given Kudos: 25903
Send PM
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   23 May 2022, 04:03
Expert Reply
krpajedrez wrote:
Carcass wrote:
OE

Quote:
This is a simultaneous/independent probability problem in that Hank and Babe's batting performances do not influence each others'. The probability that at least one player will hit a home run in today's game is (0.3)(0.2) = 0.6.


But, 0.3*0.2 = 0.06


True sir

You are perfectly correct. The book has a typo.

I edited the OA
avatar
krpajedrez
Intern
Intern
Joined: 10 May 2022
Posts: 9
Own Kudos [?]: 12 [1]
Given Kudos: 1
Send PM
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   23 May 2022, 05:11
1
I was just pointing out your calculation error.

But your logic is still wrong.
The question asks for "at least one", and you are determining the probability of both simultaneously.
User avatar
P
GreenlightTestPrep
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12188 [1]
Given Kudos: 136
Send PM

Top Member of the Month
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   23 May 2022, 06:22
1
krpajedrez wrote:
I was just pointing out your calculation error.

But your logic is still wrong.
The question asks for "at least one", and you are determining the probability of both simultaneously.

You're absolutely right. I have changed the official answer to 0.44
avatar
B
poornaabhijith
Intern
Intern
Joined: 22 Jan 2022
Posts: 9
Own Kudos [?]: 7 [1]
Given Kudos: 84
Send PM
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink] New post   03 Jun 2022, 02:07
1
We just subtract both not hitting a home run from 1 (total of all probabilities).
1-0.7*0.8=0.44.
Prep Club for GRE Bot
gmatclubot
Re: If the probabilities of Hank and Babe, two baseball players in the sam [#permalink]
03 Jun 2022, 02:07
Moderators:
adewale223
GRE Instructor
78 posts
bronaugust
GRE Forum Moderator
37 posts
BrushMyQuant
Moderator
1111 posts
VibhuAnurag
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Main navigation

Partners

GRE Resources

www.ets.org/gre | About | Terms and Conditions and Privacy Policy | Prep Club for GRE Rules | Contact