How To Find The Smallest 3 Digit Number Divisible By 6,8 And 12?

12 is a multiple of 6, so any multiple of 12 will be a multiple of 6.
8 = 2^3
12 = (2^2)*3

The number must have factors of 2^3 and 3. 8*3 = 24. The smallest 3-digit multiple of 24 is

5*24 = 120

120/6 = 20
120/8 = 15
120/12 = 10

6 has 3 digit multiples as 102, 108 ,114 ,120 ,126
8 has 3 digit multiples as 104 ,112,120,128
12has 3 digit multiples as108, 120, 132
frm abv we see that 120 is common multiple of 6 ,8, 12 so
120 is least