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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

GMAT Prep Combinations

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 65
Joined: Wed Aug 22, 2007 8:29 pm
Location: Atlanta, GA
by optimisticsam » Wed Sep 05, 2007 9:11 am
To furnish a room in a model home, a decorator is to select 2 chairs and 2 tables from collection in a warehouse that are all different from each other. If the warehouse contains 5 chairs, and if 150 combinations are possible, how many table are there?

a. 6
b. 8
c. 10
d. 15
e. 30

I was not sure how to go about this, I just ended up guessing (wrongly).

Any help would be great!

Thanks in advance!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 460
Joined: Sun Mar 25, 2007 7:42 am
Thanked: 27 times

by samirpandeyit62 » Wed Sep 05, 2007 9:30 am
here we can say

5 chairs can be selected out of 2 in 5C2 ways i.e. 10 ways
this combination for selecting chairs

now acoording to Q

total combinations =150,

i.e. 150 = combination of Chairs X combination of tables (CT)

i.e 150 = 10 X CT

so CT = 15

now CT = (nos of tables) C 2

hence (nos of tables) C 2 = 15

hence nos of tables should be 6 as 6C2 =15

so ans should be "A"
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 65
Joined: Wed Aug 22, 2007 8:29 pm
Location: Atlanta, GA

by optimisticsam » Wed Sep 05, 2007 11:42 am
Is there any quick way to solve xC2=15?

Other than the plugging and chugging the choices thru n!/(k1(n-k)!)?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1