It is currently 11 Dec 2017, 21:54

### 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

# Least common denominator

Author Message
TAGS:

### Hide Tags

Manager
Joined: 24 Jul 2010
Posts: 88

Kudos [?]: 13 [0], given: 43

### Show Tags

30 Mar 2013, 03:03
Is there an algebraic way to calculate the least common denominator (LCM) of several numbers?

Kudos [?]: 13 [0], given: 43

Director
Status: Tutor - BrushMyQuant
Joined: 05 Apr 2011
Posts: 613

Kudos [?]: 810 [1], given: 59

Location: India
Concentration: Finance, Marketing
Schools: XLRI (A)
GMAT 1: 700 Q51 V31
GPA: 3
WE: Information Technology (Computer Software)

### Show Tags

30 Mar 2013, 03:51
1
KUDOS
score780 wrote:
Is there an algebraic way to calculate the least common denominator (LCM) of several numbers?

Suppose you are calculating the least common denominator of fractions with denominators 4 and 12 then you can use the following method

2 | 4, 12
2 | 2, 6
| 1, 3

so least common denominator will be 2*2*1*3 = 12

Here, we first divided 4 and 12 by their common divisor , which is 2 and we wrote the quotient in the second row which gave us 2 and 6
then we divided 2 and 6 by their common divisor , which is 2 and we wrote the quotient in the second row which gave us 1 and 3

now 1 and 3 do not a factor other than 1 so we multiply 2 , 2, 1 and 3 to get the least common divisor which is 12

Above thing could have been done in one more way
4 | 4,12
| 1,3

LCM = 4*1*3 = 12

This is a common approach to find LCM. (and thus Least Common Denominator)

This method can also be used to find HCF
4 | 4,12
| 1,3

HCF will be 4... it is nothing but the highest common multiple of both the numbers in consideration.

The same approach can be used to 3,4 or any number of numbers
LCM of 4,8,12

4 | 4,8,12
| 1,2,3

LCM = 4*1*2*3 = 24

Hope it helps!
_________________

Ankit

Check my Tutoring Site -> Brush My Quant

GMAT Quant Tutor
How to start GMAT preparations?
How to Improve Quant Score?
Gmatclub Topic Tags
Check out my GMAT debrief

How to Solve :
Statistics || Reflection of a line || Remainder Problems || Inequalities

Kudos [?]: 810 [1], given: 59

Re: Least common denominator   [#permalink] 30 Mar 2013, 03:51
Display posts from previous: Sort by