Question

The least common multiple of 20, 24, and 45 is _____.

a) 30
b) 180
c) 360
d) 21,600

Answer 1

20|2
10|2
5|5
1

20=2^2 *5

24|2
12|2
6|2
3|3
1

24=2^3 *3

45|3
15|3
5|5
1

45=3^2 * 5

the least common multiple is : 2^3 * 3^2 *5= 8*9*5= 40*9= 360