Which of the following is true?

A. The least common multiple of 9 and 12 is greater than the greatest common factor of 36 and 72.

LCM = 36

Greatest common factor = 36

The conclusion doesn't follow

B. The greatest common factor of 12 and 24 is greater than the least common multiple of 6 and 15.

GCF = 12

Least common multiple of 6 and 15 = 60

The conclusion doesn't follow

C. The least common multiple of 20 and 12 is greater than the greatest common factor of 96 and 64.

LCM = 60

Greatest common factor = 32

LCM > Greatest common factor The conclusion holds true

D. The greatest common factor of 32 and 48 is greater than the least common multiple of 7 and 30.

GCF = 16

LCM = 210

The conclusion doesn't follow

E. The least common multiple of 10 and 12 is less than the greatest common factor of 60 and 45.[/quote]

LCM = 60

GCF = 15

The conclusion doesn't follow


Hence the correct answer is (C)
_________________

Easy peasy.

Starting with C, you immediatly see that 60 is greater than the greatest common factor of 96 and 64, which is 32.

Ans C
_________________

Let's take each statement at a time

A. LCM of 9 and 12 is greater than the GCF of 36 and 72.
LCM of 9 and 12 = 36
GCF of 36 and 72= 36
Statement A is false

B. The GCF of 12 and 24 is greater than LCM of 6 and 15.
GCF of 12 and 24 = 6
LCM of 6 and 15 = 30
Statement B is false

C. The LCM of 20 and 12 is greater than the GCF of 96 and 64.
LCM of 20 and 12 = 60
GCF of 96 and 64 = 32
Statement C is true

D. The GCF of 32 and 48 is greater than the LCM of 7 and 30.
GCF of 32 and 48 =16
LCM of 7 and 30 = 210
Statement D is false

E. The LCM of 10 and 12 is less than the GCF of 60 and 45.
LCM of 10 and 12 =60
GCF of 60 and 45 =15
Statement E is false

Correct option : C

Hello,

Is there a fast way to compute the LCM and GCF for each one (to save time)?

Thanks!

KHow