Last visit was: 25 Apr 2024, 08:29 It is currently 25 Apr 2024, 08:29

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.

Close

Request Expert Reply

Confirm Cancel
Verbal Expert
Joined: 18 Apr 2015
Posts: 28634
Own Kudos [?]: 33116 [1]
Given Kudos: 25175
Send PM
avatar
Retired Moderator
Joined: 20 Apr 2016
Posts: 1307
Own Kudos [?]: 2214 [0]
Given Kudos: 251
WE:Engineering (Energy and Utilities)
Send PM
avatar
Intern
Intern
Joined: 21 Nov 2018
Posts: 21
Own Kudos [?]: 11 [0]
Given Kudos: 0
Send PM
avatar
Supreme Moderator
Joined: 01 Nov 2017
Posts: 371
Own Kudos [?]: 442 [0]
Given Kudos: 0
Send PM
Re: A certain tin contains exactly 10 identically shaped gumdrop [#permalink]
3
Expert Reply
kunalkmr62 wrote:
We also need to calculate the probability of selecting the 1st gumdrop , which will be 1/5 for any gumdeop and then multiply the probability of selecting the 2nd gumdrop , which should be 1/9.
To make it clear would you have also ignored the probability of selecting the 1st gumdrop if the numbers would have been different ?



No...

You can choose any of the first so 10/10, the second has to be a pair of this so1/9
Total 10/10*(1/9)=1/9..

If we take the way you have taken..
Then you are calculating ways to pick up a specific gumdeop..
So (2/10)*(1/9)...
But the one you choose can be any of five so 5C1..
So 5C1*(1/5)(1/9)=5*(1/5)(1/9)=1/9
Same answer
Intern
Intern
Joined: 20 Dec 2022
Posts: 15
Own Kudos [?]: 15 [1]
Given Kudos: 249
Send PM
Re: A certain tin contains exactly 10 identically shaped gumdrop [#permalink]
1
To select first gumdrop we have 10 choices that means 10C1/10C1

for second one we will be having 1C1 / 9C1

therefore, (10C1/10C1) * (1C1 / 9C1)
1 * 1/9

So answer is 1/9
Prep Club for GRE Bot
[#permalink]
Moderators:
Moderator
1085 posts
GRE Instructor
218 posts

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