16. You have two choices for the first digit (2 or 3). With each of them you have 2 choices for the second digit. For each 2-digit number so far you have two choices for the third digit and, finally, for each of these there are 2 choices for the 4th digit.
All in all, 2*2*2*2 = 16 choices.
6,2,and3
No.
6 and 12
Any multiple of 24.
5 4/4 and3 4/4
One sure way is to multiply all of the numbers together. 8 x 5 x 3 = 120 You can check it by dividing 120 by 8, 5, and 3. You will get a whole number for each.
One way to do this is multiply 8x3=24 so 24 has both as factors. Now multiply it by 10 and you have 240. That is a 3 digit number and sill has 8 and3 as factors.
It is 30
It is: 120
15
21.
The GCF is 1.