Find the least common multiple of 12, 36 and 80.

$ 12 = 2^2 \times 3 $
$ 36 = 2^2 \times 3^2 $
$ 80 = 2^4 \times 5 $
$ \text{LCM} = 2^{\max(2,2,4)} \times 3^{\max(1,2,0)} \times 5^{\max(0,0,1)} $
$ = 2^4 \times 3^2 \times 5 $
$ = 16 \times 9 \times 5 $
= 720
Answer: 720