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

Redeem

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.

★★★★★5.0559 reviews
GMATBootcamp Starts Sep 21
Chris Peckover, Target Test Prep GMAT expert
LIVE ONLINE BOOTCAMP

Live Online Bootcamp Class with Top GMAT Expert Chris Peckover

Sep 21 to Oct 9, 2026

Schedule
Mon to Fri · 7:00 to 10:00 PM ET
Included
Live classes + 6 months of TTP OnDemand
  • Boost your GMAT score in less than one month in a live online class
  • 6 months access to TTP OnDemand video courses included
View bootcamp & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
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
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start 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

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Products of consecutive intervals

Expert replies
by saracuse » Thu Sep 17, 2009 6:38 pm
Function h(n) = product of all even numbers from 2 up to n.

if h(100) ... and if p is the small prime factor of h(100) + 1.... what is p?

a) between 10 and 20
b) btwn 20 and 30
c) btwn 30 and 40
d) greater than 40

D is the answer

I took this to mean: h(100) + 1 = [ 2 x 4 x 6 x 8.. 100 ] + 1. Not sure what to do next.

Thanks for your help!
Join the discussion
Source: — Problem Solving |

by aa2kash » Fri Sep 18, 2009 3:51 am
There is a simple rule that states that n!+1 cannot be divisible by any number less than or equal to n.

modulo arithmetic:
n! mod x (where x <= n) = 0
n! + 1 mod x = 1, therefore not divisible by x.
In this particular question the function can be written as:
h(100) + 1 = (2^50)*50! + 1
therefore it's primes are > 50

correct answer is D
Join the discussion

by viju9162 » Fri Sep 18, 2009 4:20 am
Hi aa2kash,

I didn't understand the explanation :( . is this a standar formula ?
"Native of" is used for a individual while "Native to" is used for a large group
Join the discussion

by aa2kash » Fri Sep 18, 2009 2:30 pm
Hi Viju
For better understanding of this try to analyse it by putting different values of n. for eg n=5
n!+1 --> 5! +1 =121 which is not divisible by 2,3,4,5 i.e. any number less than or equal to 5 . it is divisible by 11 .

Its a general rule therefore just remember this.
Join the discussion

by viju9162 » Sun Sep 20, 2009 12:01 am
Thank you :)
"Native of" is used for a individual while "Native to" is used for a large group
Join the discussion