I just answered this question few minutes ago
yes, you are right
If the letters are considered distinct, then the number of permutations is

.
If we count either C as the same character, then we would be double-counting - to correct this, we would simply divided by the number of ways we can choose C from the available characters, or

.
Answer:
X >>>>> Y
–1 >>>> 16
0 >>>>> 8
1 >>>>> 4
2 >>>>> 2
3 >>>>> 1
Step-by-step explanation:
From the question given above,
y = 8 × (½)ˣ
When x = –1, y =?
y = 8 × (½)ˣ
y = 8 × (½)¯¹
y = 8 × 2
y = 16
When x = 1, y =?
y = 8 × (½)ˣ
y = 8 × (½)¹
y = 8 × ½
y = 4
When x = 2, y =?
y = 8 × (½)ˣ
y = 8 × (½)²
y = 8 × ¼
y = 2
When x = 3, y =?
y = 8 × (½)ˣ
y = 8 × (½)³
y = 8 × ⅛
y = 1
SUMMARY:
X >>>>> Y
–1 >>>> 16
0 >>>>> 8
1 >>>>> 4
2 >>>>> 2
3 >>>>> 1