Answer:
1260
Step-by-step explanation:
The least common multiple is the smallest positive number which is a multiple of the two. This means 84, 36, and 15 divide into it evenly. To find the multiple:
84: 2*2*3*7
36: 2*2*3*3
15: 3*5
LCM: 2*2*3*3*5*7= 1260