Question

mmc(15x20)
mmc(20x30)
mmc(6x45)

Answer 1

15,20|2
15,10|2
15, 5 |3
5,5 |5
1,1 5.3.2.2=60


6,45|2
3,45|3
1,15|3
5 |5
1 5.3.3.2=90

Answer 2

15, 20  | 2
15, 10 | 2
15,  5 | 3
5,   5 | 5
1,   1

2 x 2 x 3 x 5 = 60
MMC = ( 15, 20 ) = 60

20, 30  | 2
10, 15 | 2
5,  15 | 3
5,  5  | 5
1,  1

2 x 2 x 3 x 5 = 60
MMC = ( 20, 30 ) = 60

6, 45   | 2
3, 15  | 3
1, 5   | 5
1, 1

2 x 3 x 5  = 30
MMC = ( 6, 45 ) = 30                :)