Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 24 Jun 2016, 23:07

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# How many positive integers less than 100 are multiples of

Author Message
CEO
Joined: 21 Jan 2007
Posts: 2756
Location: New York City
Followers: 9

Kudos [?]: 638 [0], given: 4

How many positive integers less than 100 are multiples of [#permalink]

### Show Tags

30 Oct 2007, 08:08
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

How many positive integers less than 100 are multiples of both 16 and 14?

0
1
2
3
4

How would you attack this question quickly?
Director
Joined: 11 Jun 2007
Posts: 931
Followers: 1

Kudos [?]: 126 [0], given: 0

### Show Tags

30 Oct 2007, 08:14
bmwhype2 wrote:
How many positive integers less than 100 are multiples of both 16 and 14?

0
1
2
3
4

How would you attack this question quickly?

1) you can either write out the multiples of 14 and 16 (which didn't take me very long)

14, 28, 42, 56, 70, 84, 98
16, 32, 48, 64, 80, 96

OR

2) write out the prime factorization for both (again didn't take very long)
14 = 2*7
16 = 2*2*2*2
so the LCM = 2*2*2*2*7 = 16*7 = 112

nothing under 100, so 0
Manager
Joined: 02 Aug 2007
Posts: 146
Followers: 1

Kudos [?]: 26 [0], given: 0

### Show Tags

30 Oct 2007, 08:16
Got it

Get the prime factors of 16 & 14
16 = 2^4
14 = 2*7

Unique prime factors
so 2^4 * 7 = 112

A. Zero
CEO
Joined: 21 Jan 2007
Posts: 2756
Location: New York City
Followers: 9

Kudos [?]: 638 [0], given: 4

### Show Tags

31 Oct 2007, 08:45
beckee529 wrote:
bmwhype2 wrote:
How many positive integers less than 100 are multiples of both 16 and 14?

0
1
2
3
4

How would you attack this question quickly?

1) you can either write out the multiples of 14 and 16 (which didn't take me very long)

14, 28, 42, 56, 70, 84, 98
16, 32, 48, 64, 80, 96

OR

2) write out the prime factorization for both (again didn't take very long)
14 = 2*7
16 = 2*2*2*2
so the LCM = 2*2*2*2*7 = 16*7 = 112

nothing under 100, so 0

thanks. prime factorization is much quicker.
Re: LCM   [#permalink] 31 Oct 2007, 08:45
Display posts from previous: Sort by