| View previous topic :: View next topic |
| Author |
Message |
nikhilagrawal
Just gettin' started!
Joined: 12 Jun 2008
Posts: 28
Thanks given: 1
Thanked 0 times in 0 posts
|
 Posted: Wed Jul 23, 2008 5:22 am Post subject: P and C |
 |
|
My name is AJEET. But my son accidentally types the name by interchanging a pair of letters in my name. What is the probability that despite this interchange, the name remains unchanged?
a) 5%
b) 10%
c) 20%
d) 25% |
|
| Back to top |
|
 |
|
|
sudhir3127
Moderator
Joined: 07 Jul 2008
Posts: 468
Thanks given: 0
Thanked 25 times in 23 posts
Location: INDIA
Target GMAT Score: 700+
|
| Posted: Wed Jul 23, 2008 5:35 am Post subject: |
|
|
My answer is 10 %
2/20= 10% |
|
| Back to top |
|
|
reachac
Moderator
Joined: 22 Feb 2008
Posts: 473
Thanks given: 1
Thanked 8 times in 8 posts
Location: New Delhi
Test Date: 7th Aug
Target GMAT Score: 770
GMAT Score: 780
|
| Posted: Wed Jul 23, 2008 6:29 am Post subject: |
|
|
10%
_________________
I know well what I am fleeing from but not what I am in search of. ...... |
|
| Back to top |
|
|
nikhilagrawal
Just gettin' started!
Joined: 12 Jun 2008
Posts: 28
Thanks given: 1
Thanked 0 times in 0 posts
|
| Posted: Wed Jul 23, 2008 6:53 am Post subject: |
|
|
can some one help me in determing the no of successful events.
I amy confused how we are getting 20 .. pls explain .. |
|
| Back to top |
|
|
acecoolan
Just gettin' started!
Joined: 07 May 2008
Posts: 8
Thanks given: 0
Thanked 0 times in 0 posts
|
| Posted: Wed Jul 23, 2008 7:44 pm Post subject: |
|
|
Can someone explain this ....my Probability and Perm/Comb fundaes are totally 0 ..I think
Can anyone also suggest where to start afresh on these topics? |
|
| Back to top |
|
|
|
|
Stuart Kovinsky
GMAT Instructor
Joined: 08 Jan 2008
Posts: 1014
Thanks given: 0
Thanked 144 times in 133 posts
Location: Toronto
GMAT Score: 800
|
| Posted: Wed Jul 23, 2008 9:30 pm Post subject: Re: P and C |
|
|
| nikhilagrawal wrote: | My name is AJEET. But my son accidentally types the name by interchanging a pair of letters in my name. What is the probability that despite this interchange, the name remains unchanged?
a) 5%
b) 10%
c) 20%
d) 25% |
There are 5C2 different pairs of letters in your name.
5C2 = 5!/2!3! = 5*4/2 = 10
So, there are 10 swaps that your son could make.
Only 1 of those swaps (E/E) would leave your name spelled correctly. So, there's a 1/10 chance that your name will still be fine: choose (b).
Just curious, why aren't there 5 answer choices?
_________________
Stuart Kovinsky, B.A. LL.B.
Academic Co-ordinator
Kaplan Test Prep & Admissions
Toronto Office
1-800-KAP-TEST |
|
| Back to top |
|
|
|
