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
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & 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.

GMAT Prep Question

Expert replies
by bjahn » Sat Feb 02, 2008 2:48 pm
The function f is defined for all positive integers by the following rule:
f(n) is the number of positive integers each of which is less than n and has no positive factor in common with n other than 1. If p is any prime number then f(p)= ??

(a) p-1

(b) p-2

(c) (p+1) / 2

(d) (p-1) / 2

(e) 2

I dont get why the answer is a, i thought it would be b
Join the discussion
Source: — Problem Solving |

by cris » Sat Feb 02, 2008 2:53 pm
It has to be p-1 because you count 1. With p-2 you will not be counting 1.

Correct me if I am wrong
Join the discussion

by bjahn » Sat Feb 02, 2008 4:30 pm
But doesn't the question say "other than 1" ?? Doesn't this mean 1 should not be counted?
Join the discussion

by Stuart@KaplanGMAT » Sat Feb 02, 2008 6:06 pm
bjahn wrote:But doesn't the question say "other than 1" ?? Doesn't this mean 1 should not be counted?
1 is a positive integer that has no factors in common with n other than 1 (the "other than 1" refers to the factors, not to the integer itself). Therefore, count 1.
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
Join the discussion