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

How to solve factorials - Shortcut?

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 301
Joined: Tue Apr 22, 2008 6:07 am
Thanked: 2 times
by beater » Sun Sep 21, 2008 12:28 pm
Could one of you please explain a time effective method to solve factorials. For eg: How would you go about solving 30!

Thanks
Top
Join the discussion
Source: — Problem Solving |
GMAT Instructor
Posts: 1223
Joined: Thu May 01, 2008 3:29 pmFollowed by: 15 members
Location: Los Angeles, CA
Thanked: 185 times

by VP_Jim » Sun Sep 21, 2008 12:35 pm
You'd never have to calculate 30! (or anything even close to it) on the GMAT. It's good to know the factorials up to, say, 5!, though.

Remember: the vast majority of the time, the GMAT does NOT test your computational abilities. If you find yourself doing lots of math, you're probably doing something wrong.
Jim S. | GMAT Instructor | Veritas Prep
Top
Join the discussion
User avatar
Legendary Member
Posts: 871
Joined: Wed Aug 13, 2008 7:48 am
Thanked: 48 times

by stop@800 » Sun Sep 21, 2008 1:07 pm
Where are you required to solve this factorial?

The question must be expecting you to extract something from this number like units place or no of zeros or something else that can be obtained without calculating the value.
Top
Join the discussion
Master | Next Rank: 500 Posts
Posts: 301
Joined: Tue Apr 22, 2008 6:07 am
Thanked: 2 times

by beater » Sun Sep 21, 2008 3:27 pm
I did not come across a question that required solving for 30!. But, I was just curious if there was a shortcut to solve factorials. Thanks!
Top
Join the discussion
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Sun Apr 14, 2013 5:44 pm

by MediatorOfDeath » Sun Apr 14, 2013 5:49 pm
There is a shortcut to finding factorials. It lets you do about half of the work, and get the same answer. I just recently discovered it, and made a website to put it on. Here is the link. If you are looking for speed, I would use the first method I share, and not worry about the second. Enjoy! :)
Top
Join the discussion

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16206
Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members
Location: Vancouver, BC
Thanked: 5254 times
GMAT Score:770

by Brent@GMATPrepNow » Mon Apr 15, 2013 4:22 am
As VP_Jim mentioned, the GMAT will never require you to perform such a series of tedious calculations. However, when dealing with the combination formula, nCr = n!/(r!)(n-r!), you will have to work with several factorials. In these cases, there is a nice shortcut that will allow you to calculate combinations (like 12C3) in your head.

Here's our free video on this topic: https://www.gmatprepnow.com/module/gmat-counting?id=789

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion