BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Disciples with Tiffany

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

Disciples with Tiffany

by sanju09 » Fri Feb 20, 2009 3:07 am
How many disciples does Tiffany have?

(1) there are between 200 and 500 lists she could make consisting of the names of at least 2 of her disciples.

(2) there are 28 ways that she could decide which 2 disciples she will recommend promoting.
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Data Sufficiency |
User avatar
Master | Next Rank: 500 Posts
Posts: 319
Joined: Wed Feb 04, 2009 10:32 am
Location: Delhi
Thanked: 84 times
Followed by:9 members

by sureshbala » Fri Feb 20, 2009 5:24 am
Clearly the first statement alone is not sufficient.

From the second statement: If there are n disciples it is given that nC2 = 28 i.e n(n-1)=56. So n = 8.

Hence second statement alone is sufficient
Top
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

by sanju09 » Fri Feb 20, 2009 5:37 am
sureshbala wrote:Clearly the first statement alone is not sufficient.

From the second statement: If there are n disciples it is given that nC2 = 28 i.e n(n-1)=56. So n = 8.

Hence second statement alone is sufficient
:) What if OA is D, sir! Will you support that?
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 319
Joined: Wed Feb 04, 2009 10:32 am
Location: Delhi
Thanked: 84 times
Followed by:9 members

by sureshbala » Fri Feb 20, 2009 6:11 am
sanju09 wrote:
sureshbala wrote:Clearly the first statement alone is not sufficient.

From the second statement: If there are n disciples it is given that nC2 = 28 i.e n(n-1)=56. So n = 8.

Hence second statement alone is sufficient
:) What if OA is D, sir! Will you support that?
Yes...the answer will be D. I misunderstood the first statement...Should get out of my office quickly....

Anyway....

From first statement if n is the number of disciples, the number of ways in which she can choose at least 2 disciples is 2^n - (nC0 + nC1) = 2^n - (n+1)

Given 200<2^n -(n+1)<500

There is only one natural number satisfying this which is 8.

Hence D will be the answer
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 319
Joined: Wed Feb 04, 2009 10:32 am
Location: Delhi
Thanked: 84 times
Followed by:9 members

by sureshbala » Fri Feb 20, 2009 6:13 am
By the way Sanju, nice to see you here as well...Hope you are doing well
Top
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

by sanju09 » Fri Feb 20, 2009 6:34 am
sureshbala wrote:By the way Sanju, nice to see you here as well...Hope you are doing well
:) I am sure you listen to Hindi songs...

Aji rooth kar ab kaha.n jaaiyega

Jaha.n jaaiyega hamei.n paaiyega

Do you know Suresh, yours have been the quickest way to solve this problem, so far, though after realizing that you are in office, I am also leaving now, bye and good night! B-)
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Post new topic Post Reply
• Page 1 of 1