Answer:
1: 216 selections
2: 120 selections
Step-by-step explanation:
1:
we have 6 different colors and we can choose the same color repeatedly, so for each of the 3 dogs, we have 6 possibilities, so the number of combinations is 6*6*6 = 216 selections.
2:
we have 6 different colors and we can't repeat a color, so the first collar has 6 possibilities, the second has 5 possibilities (one color was already chosen), and the third collar has 4 possibilities (two already chosen), so the number of selections is 6*5*4 = 120.
I could be wrong but I got 28. I devided 420 by 15
