It is currently 24 Sep 2017, 00:04

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# The function f is defined for all positive integers n by the

Author Message
VP
Joined: 22 Nov 2007
Posts: 1079

Kudos [?]: 663 [0], given: 0

The function f is defined for all positive integers n by the [#permalink]

### Show Tags

11 Mar 2008, 23:26
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

The function f is defined for all positive integers n 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)=

p - 1
p - 2
(p + 1)/2
(p - 1)/2
2

Kudos [?]: 663 [0], given: 0

Director
Joined: 10 Sep 2007
Posts: 936

Kudos [?]: 327 [0], given: 0

### Show Tags

12 Mar 2008, 08:12
Answer should be P - 1.
All the numbers between 1 and P (excluding P) are less than P and has no positive factor in common with P other than 1 (because P is a prime number so factors other than 1 and P itself).

Kudos [?]: 327 [0], given: 0

VP
Joined: 22 Nov 2007
Posts: 1079

Kudos [?]: 663 [0], given: 0

### Show Tags

14 Mar 2008, 03:29
abhijit_sen wrote:
Answer should be P - 1.
All the numbers between 1 and P (excluding P) are less than P and has no positive factor in common with P other than 1 (because P is a prime number so factors other than 1 and P itself).

yes it is. it could be useful to try with numbers:

if P is 2 then we must have only 2 members: 1 and 2, so choice must be p-1
if P is 3 then we must have 1 and 2 as other members, so choice could be p-1 or p+1/2.

using both examples we would have p-1

Kudos [?]: 663 [0], given: 0

Re: gprep functions   [#permalink] 14 Mar 2008, 03:29
Display posts from previous: Sort by