Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 563 reviewsTarget Test Prep

Permutation with Flash Cards

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
User avatar
Master | Next Rank: 500 Posts
Posts: 200
Joined: Sun Jun 17, 2007 10:46 am
Location: Canada
Thanked: 9 times
by beeparoo » Thu May 29, 2008 12:44 pm
A first grade teacher uses ten flash cards, each numbered from 1 to10, to teach her students to order numbers correctly. She has students choose four flash cards randomly, then arrange the cards in ascending order. One day, she removes the cards '2' and '4' from the deck. On that day, how many different correct arrangements of four randomly selected cards are possible?

A. 70
B. 210
C. 336
D. 840
E. 1680

OA after a few responses... Promise!
Top
Join the discussion
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 58
Joined: Fri Apr 04, 2008 12:36 pm
Thanked: 4 times
GMAT Score:680

Re: Permutation with Flash Cards

by mim3 » Thu May 29, 2008 1:47 pm
beeparoo wrote:A first grade teacher uses ten flash cards, each numbered from 1 to10, to teach her students to order numbers correctly. She has students choose four flash cards randomly, then arrange the cards in ascending order. One day, she removes the cards '2' and '4' from the deck. On that day, how many different correct arrangements of four randomly selected cards are possible?

A. 70
B. 210
C. 336
D. 840
E. 1680

OA after a few responses... Promise!
I'm going to go with A.
8p4= 1680
#of ways to arrange four cards: 24

1680/24= 70

Not confident in that answer at all.
Top
Join the discussion
User avatar
Senior | Next Rank: 100 Posts
Posts: 42
Joined: Fri Mar 14, 2008 1:56 am
Location: India
Thanked: 4 times
GMAT Score:730

by getneonow » Thu May 29, 2008 10:51 pm
Overall there should be 10 cards but 2 are removed now.

So 8 cards left out.

Now if we select any 4 cards from these 8, we can always arrange them in ascending order since all the cards are distinct.

Thus ans will be 8C4 = 70

Neo
MBA : My passion and My pursuit
Top
Join the discussion
User avatar
Master | Next Rank: 500 Posts
Posts: 200
Joined: Sun Jun 17, 2007 10:46 am
Location: Canada
Thanked: 9 times

by beeparoo » Fri May 30, 2008 11:17 am
Ans is A. 70

Good job, guys

Sandra
Top
Join the discussion
Master | Next Rank: 500 Posts
Posts: 131
Joined: Mon May 05, 2008 10:46 am
Thanked: 1 times

by Mclaughlin » Sat May 31, 2008 12:21 pm
getneonow wrote:Overall there should be 10 cards but 2 are removed now.

So 8 cards left out.

Now if we select any 4 cards from these 8, we can always arrange them in ascending order since all the cards are distinct.

Thus ans will be 8C4 = 70

Neo
Stupid question but in your asnwer you wrote 8C4. what does that mean? what does C represent in this equation?
Top
Join the discussion
User avatar
GMAT Instructor
Posts: 3224
Joined: Tue Jan 08, 2008 2:40 pmFollowed by: 614 members
Location: Toronto
Thanked: 1710 times
GMAT Score:800

by Stuart@KaplanGMAT » Sat May 31, 2008 8:49 pm
Mclaughlin wrote:
getneonow wrote:Overall there should be 10 cards but 2 are removed now.

So 8 cards left out.

Now if we select any 4 cards from these 8, we can always arrange them in ascending order since all the cards are distinct.

Thus ans will be 8C4 = 70

Neo
Stupid question but in your asnwer you wrote 8C4. what does that mean? what does C represent in this equation?
"C" represents "choose" or "combination".

nCk = n!/k!(n-k)!

when n = total # of objects and k = the # chosen

In this question, we have 8 total cards and we're choosing 4 of them. If we want to know the number of subgroups of 4 that we can choose out of 8 total, we have:

n=8, k=4

8C4 = 8!/4!(8-4)! = 8!/4!4! = 8*7*6*5*4*3*2/4*3*2*4*3*2 = 8*7*6*5/4*3*2 = 7*6*5/3 = 7*2*5 = 70
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
Top
Join the discussion