The greatest common factor is the the greatest common number that shows up in all the sets listed numbers
1) so first you want to list out all the numbers that can multiply into 12. That would be 1x12, 6x2, and 3x4.
So, The multiples of 12 are: 1 and 12, 6 and 2, and 3 and 4 so we can list them out from smallest to largest: 1,2,3,4,6,12
The multiples of 24 are: 1 and 24, 2 and 12, 3 and 8, and 4 and 6; so we can do the same thing as the first one. 1,2,3,4,6,8,12,24
The multiples of 40 are, 1 and 40, 2 and 20, 4 and 10, and 8 and 5; the listed numbers are: 1,2,4,5,8,10,20,40
So the greatest common number (factor) between all the lists of numbers are 4
The Least common multiple is the lowest common number that each of the original numbers can be multiplied to get
2) list out the answers to what two can be multiplied by; 2x1=2, 2x2=4, 2x3=6, 2x4=8, 2x5=10, 2x6= 12 2x7=14, 2x8=16, 2x9=18, 2x10=20, 2x11=22, 2x12=24, 2x13=26, 2x14=28, 2x15=30
So the list of multiples for two can be: 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30
list out the answers to what three can be multiplied by; 3x1=3, 3x2=6, 3x3=9, 3x4=12, 3x5= 15, 3x6=18, 3x7=21, 3x8= 24, 3x9= 27, 3x10= 30
So the list of multiples for three can be: 3,6,9,12,15,18,21,24,27,30
list out the answers to what five can be multiplied by; 1x5=5, 2x5=10, 3x5=15, 4x5=20, 5x5=25, 6x5=30
So the list of multiples for five can be: 5,10,15,20,25,30
The least common multiple out of the lists is 30 since they all share it
If you have any more questions i will be glad to help!
