GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 15 Dec 2019, 16:24

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

If 5n + 4 is divisible by 3 and 6m + 2 is divisible by 5 (m and n are

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
VP
VP
User avatar
D
Joined: 31 Oct 2013
Posts: 1492
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
CAT Tests
If 5n + 4 is divisible by 3 and 6m + 2 is divisible by 5 (m and n are  [#permalink]

Show Tags

New post 01 Oct 2018, 12:20
1
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

61% (02:18) correct 39% (02:36) wrong based on 25 sessions

HideShow timer Statistics

If 5n + 4 is divisible by 3 and 6m + 2 is divisible by 5 (m and n are non negative integers), what is the lowest common value for m and n ?

A) 4
B) 7
C) 8
D) 13
E) 15
Intern
Intern
User avatar
B
Joined: 14 Aug 2018
Posts: 20
Location: United States (WA)
GMAT 1: 670 Q43 V40
GMAT 2: 750 Q47 V47
GPA: 3.3
WE: Education (Education)
Re: If 5n + 4 is divisible by 3 and 6m + 2 is divisible by 5 (m and n are  [#permalink]

Show Tags

New post 01 Oct 2018, 12:46
1
There is a math way to get to the right answer, but it is probably a to faster to work backward from the answer choices. Substitute the answer choices into the equations and see which is the lowest answer choice that works.

Before you start this method, pause and think - is it easier and faster to check for divisibility by 5 or by 3? Notice how the testmaker put the divisible by 5 equation second - this is on purpose. Most students will work with the first equation first - work smarter by doing the easier and faster thing first.

A number is divisible by 5 if it ends in either 0 or 5. So, for 6m+2 we only need to check the units digit

A. 6(4) + 2 ends in 6 eliminate
B. 6(7) + 2 ends in 4 eliminate
C. 6(8) + 2 ends in 0. keep. Do second equation. 5(8)+ 4 = 44. Not divisible by 3. (Div by three if digits add to a number divisible by 3. 4+4 = 8, which is not divisible by 3)
D. 6(13) + 2 ends in 0. Keep. Do second equation 5(13) + 4 = 69. Is divisible by 3. Is right.
_________________
Jayson Beatty
Indigo Prep
http://www.indigoprep.com
GMAT Club Bot
Re: If 5n + 4 is divisible by 3 and 6m + 2 is divisible by 5 (m and n are   [#permalink] 01 Oct 2018, 12:46
Display posts from previous: Sort by

If 5n + 4 is divisible by 3 and 6m + 2 is divisible by 5 (m and n are

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





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