Last visit was: 26 Jul 2024, 19:58 It is currently 26 Jul 2024, 19:58
Close
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
Your Progress

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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
SORT BY:
Date
Tags:
Show Tags
Hide Tags
Math Expert
Joined: 02 Sep 2009
Posts: 94619
Own Kudos [?]: 644171 [11]
Given Kudos: 86770
Send PM
Director
Director
Joined: 26 Jan 2019
Posts: 508
Own Kudos [?]: 453 [4]
Given Kudos: 118
Location: India
Send PM
GMAT Club Legend
GMAT Club Legend
Joined: 08 Jul 2010
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Posts: 6042
Own Kudos [?]: 13835 [1]
Given Kudos: 125
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Send PM
RC & DI Moderator
Joined: 02 Aug 2009
Status:Math and DI Expert
Posts: 11475
Own Kudos [?]: 34633 [0]
Given Kudos: 325
Send PM
Re: Given that x is a positive integer such that x 75, which of the foll [#permalink]
Expert Reply
Bunuel wrote:
Q = x^3 − x

Given that x is a positive integer such that x ≥ 75, which of the following is the remainder when Q is divided by 6?

A. 0
B. 1
C. 3
D. 5
E. Cannot be determined by the information provided



The answer does not depend on value of x.

\(x^3-x=x(x^2-1)=x(x-1)(x+1)\), where x is an integer.
So, (x-1), x and (x+1) are consecutive integers.

The product of 3 consecutive integers will have at least one even number and one multiple of 3.
That is, the product of 3 consecutive integers will always be divisible by 2*3 or 6.


A
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 19213
Own Kudos [?]: 22731 [0]
Given Kudos: 286
Location: United States (CA)
Send PM
Re: Given that x is a positive integer such that x 75, which of the foll [#permalink]
Expert Reply
Bunuel wrote:
Q = x^3 − x

Given that x is a positive integer such that x ≥ 75, which of the following is the remainder when Q is divided by 6?

A. 0
B. 1
C. 3
D. 5
E. Cannot be determined by the information provided


We can rewrite the expression x^3 - x as x(x^2 - 1) = x(x - 1)(x + 1) = (x - 1)(x)(x + 1). Thus, Q is a product of three consecutive integers. Since the product of n consecutive integers is always divisible by n!, the product of three consecutive integers is divisible by 3! = 6, which means the remainder when Q is divided by 6 is 0.

Answer: A
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 34111
Own Kudos [?]: 854 [0]
Given Kudos: 0
Send PM
Re: Given that x is a positive integer such that x 75, which of the foll [#permalink]
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
GMAT Club Bot
Re: Given that x is a positive integer such that x 75, which of the foll [#permalink]
Moderator:
Math Expert
94619 posts