According to the meaning of the question, deer, elephant and rabbit are arranged in three rooms, one for each animal.

Then some situations may be as follows:

1, deer, elephant, rabbit

2. Deer, rabbits and elephants

3. Rabbits, deer and elephants

4. Rabbits, elephants and deer

5. Elephants, deer and rabbits

6. Elephants, rabbits and deer

So there are six arrangements for a * * *.

Extended data:

This kind of problem belongs to the combinatorial problem in mathematics.

Combination is one of the important concepts in mathematics. Taking out M different elements (0≤m≤n) from N different elements at a time and synthesizing a group regardless of their order is called selecting the combination of M elements from N elements without repetition. The total number of all such combinations is called the combination number, and the calculation formula of this combination number is

or

The total number of combinations is the sum of all combinations of 0, 1, 2, …, n different elements taken out from n different elements at a time, that is

The total number of combinations of a group of n elements is the number of its subsets.

The properties of the combination number formed by taking out M different elements from N different elements at one time are as follows:

Using these two properties, we can simplify the calculation of combination number and prove the problems related to combination number.