Last visit was: 18 Nov 2024, 22:54 It is currently 18 Nov 2024, 22:54

Close

GRE Prep 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 GRE 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
User avatar
Senior Manager
Senior Manager
Joined: 10 Feb 2020
Posts: 496
Own Kudos [?]: 348 [11]
Given Kudos: 299
Send PM
avatar
Manager
Manager
Joined: 09 Mar 2020
Posts: 164
Own Kudos [?]: 202 [0]
Given Kudos: 0
Send PM
User avatar
Senior Manager
Senior Manager
Joined: 10 Feb 2020
Posts: 496
Own Kudos [?]: 348 [0]
Given Kudos: 299
Send PM
User avatar
Intern
Intern
Joined: 03 Aug 2020
Posts: 8
Own Kudos [?]: 13 [0]
Given Kudos: 0
Send PM
Re: n is a positive integer and 98^98 is divisible by 7^n. [#permalink]
1
I got D on this. 7^196 = 49^98 which is significantly less than 98^98. n could = 1, as any multiple of 98 will be divisible by 7, but it will also surely be divisible by iterations of 7^n far beyond 196, since 49^98 is so much less than 98^98.
avatar
Manager
Manager
Joined: 09 Mar 2020
Posts: 164
Own Kudos [?]: 202 [0]
Given Kudos: 0
Send PM
Re: n is a positive integer and 98^98 is divisible by 7^n. [#permalink]
stinkydiver wrote:
I got D on this. 7^196 = 49^98 which is significantly less than 98^98. n could = 1, as any multiple of 98 will be divisible by 7, but it will also surely be divisible by iterations of 7^n far beyond 196, since 49^98 is so much less than 98^98.


Yes, this is correct, if n = 1, even then it can divide 98 ^ 98 and if n = 198, it can still divide it. Answer is D
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12192 [3]
Given Kudos: 136
Send PM
n is a positive integer and 98^98 is divisible by 7^n. [#permalink]
2
1
Bookmarks
Farina wrote:
n is a positive integer and \(98^{98}\) is divisible by \(7^n\).

Quantity A
Quantity B
n
196



\(98 = (2)(7)(7) = (2^1)(7^2)\)

So, \(98^{98}\) = \([(2^1)(7^2)]^{98}= (2^{98})(7^{196})\)

At this point we can see that....
\((2^{98})(7^{196})\) is divisible by \(7^1\)
\((2^{98})(7^{196})\) is divisible by \(7^2\)
\((2^{98})(7^{196})\) is divisible by \(7^3\)
.
.
.
\((2^{98})(7^{196})\) is divisible by \(7^{195}\)
\((2^{98})(7^{196})\) is divisible by \(7^{196}\)

In other words \(n\) can have any value from \(1\) to \(196\) inclusive

If \(n=1\), Quantity B is greater
If \(n=196\), the two quantities are equal

Answer: D
User avatar
GRE Prep Club Legend
GRE Prep Club Legend
Joined: 07 Jan 2021
Posts: 5020
Own Kudos [?]: 74 [0]
Given Kudos: 0
Send PM
Re: n is a positive integer and 98^98 is divisible by 7^n. [#permalink]
Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep 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.
Prep Club for GRE Bot
Re: n is a positive integer and 98^98 is divisible by 7^n. [#permalink]
Moderators:
GRE Instructor
78 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne