Last visit was: 19 Dec 2024, 00:17 It is currently 19 Dec 2024, 00:17

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
avatar
Intern
Intern
Joined: 24 May 2016
Posts: 33
Own Kudos [?]: 29 [0]
Given Kudos: 0
Send PM
User avatar
Sherpa Prep Representative
Joined: 15 Jan 2018
Posts: 147
Own Kudos [?]: 363 [0]
Given Kudos: 0
Send PM
Verbal Expert
Joined: 18 Apr 2015
Posts: 30387
Own Kudos [?]: 36755 [0]
Given Kudos: 26086
Send PM
avatar
Manager
Manager
Joined: 27 Sep 2017
Posts: 110
Own Kudos [?]: 82 [0]
Given Kudos: 0
Send PM
Re: Quantitative Reasoning [#permalink]
SherpaPrep wrote:
10! means 10x9x8x7x6x5x4x3x2x1. Just getting that out of the way. So if we want to know the maximum value of x, we basically need to count up how many 3s there are in 10!. Every third integer is divisible by 3, so that's 3, 6, and 9. It's a trap to think you're done here. We should also realize that every ninth integer is divisible by 9, and 9 has two 3s as factors. In other words, 9 should count twice. So x = 4, not 3.

Using similar logic, we know that 5 and 10 have factors of 5, so y must be 2. Thus, 2y = 4 and the answer is C.



Are u really sure ANS is C, I don't see "2y", where is it from?
avatar
Manager
Manager
Joined: 22 Feb 2018
Posts: 163
Own Kudos [?]: 215 [0]
Given Kudos: 0
Send PM
Re: 10! is divisible [#permalink]
2
correct: A
we should write the number 10! into it's simplest form consisting of just prime numbers.
10! = 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1 = \(2^8 *3^4 * 5^2 * 7\)
10! = \(3^x * 5^y\) so x = 4 and y = 2
so x is bigger than y

Originally posted by Fatemeh on 15 Mar 2018, 15:58.
Last edited by Carcass on 16 Mar 2018, 02:20, edited 1 time in total.
Edited by Carcass
avatar
Manager
Manager
Joined: 15 Feb 2018
Posts: 53
Own Kudos [?]: 34 [0]
Given Kudos: 0
Send PM
Re: 10! is divisible [#permalink]
How is the answer C? I am getting A. I have x = 4 and y = 2.
User avatar
Manager
Manager
Joined: 26 Jun 2017
Posts: 102
Own Kudos [?]: 71 [0]
Given Kudos: 0
Send PM
Re: 10! is divisible [#permalink]
1
The sad part of story is that I spent 10 minutes from my valuable time trying to prove me wrong :-D while I was right
avatar
Intern
Intern
Joined: 11 Jan 2018
Posts: 44
Own Kudos [?]: 104 [0]
Given Kudos: 0
Send PM
Re: 10! is divisible [#permalink]
Please correct the OA of this question.

Choice A is correct.
Verbal Expert
Joined: 18 Apr 2015
Posts: 30387
Own Kudos [?]: 36755 [0]
Given Kudos: 26086
Send PM
Re: 10! is divisible [#permalink]
1
Expert Reply
Done. Thank you guys for your collaboration.

However, next time posts like this one will be closed.

Regards
Prep Club for GRE Bot
Re: 10! is divisible [#permalink]
Moderators:
GRE Instructor
88 posts
GRE Forum Moderator
37 posts
Moderator
1115 posts
GRE Instructor
234 posts

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