Question

what is the gcf of 20,30,36,45

Answer 1

GCF (Greatest Common Factor) or HCF (Highest Common Factor) of 20, 30, 36, 45

So first let's find the GCF of 20 and 30

20 ) 30 ( 1
.........20
......-------
.........10 ) 20 ( 2
.................20
..............-------
.................0

So GCF of 20 and 30 is 10

Let's now find the GCF of 10 and 36

10 ) 36 ( 3
........30
.....-------
.........6 ) 10 ( 1
.................6
.............-------
................4 ) 6 ( 1
..…………..…..4
...................-----
.....................2 ) 4 ( 2
...........................4
.......................------
..........................0

So GCF of 10 and 36 is 2

Let's find the GCF of 2 and 45

2 ) 45 ( 22
.....44
....------
........1 ) 2 ( 1
.............1
..........-----
.............1 ) 1 ( 1
..................1
..............------
.................0

So GCF of 2 and 45 is 1

So GCF of 20, 30, 36, 45 is 1

Answer is 1.

Hope it helps !!!

Answer 2

Answer:

Step-by-step explanation:

First we have to find out the factors of 20,30,36 and 45

Factors of 20 : 1,2,4,5,10

Factors of 30 : 1,2,3,5,6,10,15

Factors of 36 : 1, 2,3,6,12,18

Factors of 45 : 1,3,5,9,15

As There are no common factor between them

GCF of 20,30,36,45 = 1

"Somtimes 1 is only the common factor "