Common factors: 3, 5, 15.
HCF: 15.
To work out:
Make a factor tree or ladder. (Ignore the dashes)
----45
---/---\
--3----15
-------/---\
------3----5
We cannot go any further as 3 & 5 are prime.
Therefore 45 = 3 x 3 x 5.
(same with 60) 60 = 2 x 2 x 3 x 5.
The easiest way is to now make a venn diagram. Put the numbers that appear in both lists in the intersection. (3 and 5 but do not put both threes in)
my venn diagram--->(3)(3, 5) (1, 2)
Then, times the numbers in the intersection together... and voila! You get 15 which is the HCF!
--To find the LCM, multiply all the numbers in the VENN DIAGRAM together. =] \AT
The highest common integral factor is 5, because 25 = 52, five is an integral factor of both 45 and 60, and 25 is not an integral factor of either 45 or 60.
the GCF of 45 and 60 is 15
For 45, 60, 90 the GCF = 15
The greatest common factor of the numbers 45 and 60 is 15.
15
15
15
15
15
1
The highest common factor 15
The Greatest Common Factor (GCF) is: 15