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

 It is currently 19 Oct 2018, 00:43

### 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

# How many two-digit numbers are divisible by both 5 and 6?

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 50001
How many two-digit numbers are divisible by both 5 and 6?  [#permalink]

### Show Tags

16 Oct 2017, 01:30
00:00

Difficulty:

5% (low)

Question Stats:

91% (00:37) correct 9% (00:32) wrong based on 60 sessions

### HideShow timer Statistics

How many two-digit numbers are divisible by both 5 and 6?

(A) none
(B) one
(C) two
(D) three
(E) more than three

_________________
Senior SC Moderator
Joined: 22 May 2016
Posts: 2034
How many two-digit numbers are divisible by both 5 and 6?  [#permalink]

### Show Tags

16 Oct 2017, 03:36
Bunuel wrote:
How many two-digit numbers are divisible by both 5 and 6?

(A) none
(B) one
(C) two
(D) three
(E) more than three

Two-digit numbers: 10 to 99

Divisible by 5 and 6 means:
For 5, must end in 5 or 0
For 6: must be divisible by 2 and 3

Use those prime factors: 5, 2, and 3
LCM = (5 * 2 * 3) = 30

30 is one multiple. Multiply by increasing integers

(30 * 1 = 30)
30 * 2 = 60
30 * 3 = 90

Next multiple of 30 is 120. Too large

There are three two-digit numbers divisible by 5 and 6: 30, 60, and 90

_________________

The only thing more dangerous than ignorance is arrogance.
-- Albert Einstein

Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 3886
Location: United States (CA)
Re: How many two-digit numbers are divisible by both 5 and 6?  [#permalink]

### Show Tags

17 Oct 2017, 11:49
Bunuel wrote:
How many two-digit numbers are divisible by both 5 and 6?

(A) none
(B) one
(C) two
(D) three
(E) more than three

If a number is divisible by both 5 and 6, then it’s divisible by their LCM, which is 30. Thus, we need to find the number of two-digit numbers that are multiples of 30. We have:

30, 60, and 90

_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Manager
Joined: 09 Aug 2017
Posts: 62
Location: United States
Concentration: Technology
GMAT 1: 640 Q44 V33
GMAT 2: 630 Q47 V29
WE: Research (Investment Banking)
Re: How many two-digit numbers are divisible by both 5 and 6?  [#permalink]

### Show Tags

22 Oct 2017, 15:07
D, three.
30, 60 and 90 all divisible by 5 and 6.
_________________

I'd love to hear any feedback or ways to improve my problem solving. I make a lot of silly mistakes. If you've had luck improving on stupid mistakes, I'd love to hear how you did it.

Also, I appreciate any kudos.

Re: How many two-digit numbers are divisible by both 5 and 6? &nbs [#permalink] 22 Oct 2017, 15:07
Display posts from previous: Sort by