Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 21 Apr 2015, 05:12

### GMAT 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

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

Practice
Pays

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# An applicant has to go through 3 successive tests.

Author Message
TAGS:
Director
Joined: 16 Aug 2005
Posts: 947
Location: France
Followers: 1

Kudos [?]: 10 [0], given: 0

An applicant has to go through 3 successive tests. [#permalink]  20 May 2006, 05:08
An applicant has to go through 3 successive tests. Probability of her passing the first test is P. Probability of passing successive tests are P or P/2 according to whether she passed the last test or not. She is selected if she passes as least 2 tests. In terms of P, what is the probability of her selection?

A. ((P^2)/2).(1-P)
B. 2P.(1-P^2)
C. 2.(1-P).P^2
D. 2.P^2 - P^3
E. 4.P^2 - P^4
Manager
Joined: 13 Dec 2005
Posts: 224
Location: Milwaukee,WI
Followers: 1

Kudos [?]: 7 [0], given: 0

very good question . According to me the answer should be D.

she will pass in following scenario

PPP --->P*P*P
PPF --->P*P*(1-p)
PFP --->p*(1-p)*(p/2)
FPP --->(1-p)*(p/2)*P

adding all of the four you get (2*P^2) - P^3

I'm curious to know the OA .
SVP
Joined: 01 May 2006
Posts: 1805
Followers: 8

Kudos [?]: 98 [0], given: 0

(D) as well
VP
Joined: 29 Dec 2005
Posts: 1349
Followers: 7

Kudos [?]: 30 [0], given: 0

Re: Probability - Tests [#permalink]  20 May 2006, 05:44
gmatmba wrote:
An applicant has to go through 3 successive tests. Probability of her passing the first test is P. Probability of passing successive tests are P or P/2 according to whether she passed the last test or not. She is selected if she passes as least 2 tests. In terms of P, what is the probability of her selection?

A. ((P^2)/2).(1-P)
B. 2P.(1-P^2)
C. 2.(1-P).P^2
D. 2.P^2 - P^3
E. 4.P^2 - P^4

go with D.

= p^3 + [p^2(1-p)] + [p(1-p)(p/2)] + [(1-p)(p/2)p]
= p^3 + p^2-p^3 + 2p(1-p)(p/2)
= p^2 + p^2(1-p)
= p^2 + p^2 - p^3
= 2 p^2 - p^3
VP
Joined: 29 Dec 2005
Posts: 1349
Followers: 7

Kudos [?]: 30 [0], given: 0

ipc302 wrote:
very good question . According to me the answer should be D.

she will pass in following scenario

PPP --->P*P*P
PPF --->P*P*(1-p)
PFP --->p*(1-p)*(p/2)
FPP --->(1-p)*(p/2)*P

adding all of the four you get (2*P^2) - P^3

I'm curious to know the OA .

wow same approach...
Similar topics Replies Last post
Similar
Topics:
3 Tips for Round 2 MBA Application Success 0 29 Nov 2014, 10:54
3 Tips for Round 2 MBA Application Success 0 29 Nov 2014, 10:52
2 An HR Manager has to go through a pile of resumes 5 20 May 2014, 14:03
A Tale of 3 Successful MBA Applicants. Admissionado Lecture. 3 13 Nov 2012, 12:46
I am going through a period of questionning but the success 13 27 Sep 2006, 06:59
Display posts from previous: Sort by