Answer:
4096.
Explanation:
We have been given that Dave wants to buy a new collar for each of his 4 cats. The collars come in a choice of 8 different colors. We are asked to find the number of selections of collars for the 4 cats if repetitions of colors are allowed.
Since repetitions are allowed, so collars for each cat be chosen in 8 different ways.
Total number of selections would be

Therefore, there are 4096 possible selections of collars.