Ten buses are plying between two places A and B. In how many ways a person can travel from A to B and come back? 

Answer

To solve the problem of how many ways a person can travel from A to B and come back, we can break down the journey into two parts: the journey from A to B and the return journey from B to A.

### Step-by-Step Solution:

1. **Identify the number of buses available**:
There are 10 buses operating between the two places A and B.

2. **Calculate the ways to travel from A to B**:
Since there are 10 buses, a person can choose any one of these 10 buses to travel from A to B. Therefore, there are 10 ways to travel from A to B.

3. **Calculate the ways to travel from B to A**:
Similarly, when the person is returning from B to A, they again have 10 buses to choose from. Hence, there are also 10 ways to travel from B to A.

4. **Combine the two parts of the journey**:
The total number of ways to complete the round trip (A to B and back to A) is the product of the number of ways to travel from A to B and the number of ways to travel from B to A.
\[ \text{Total ways} = (\text{Ways from A to B}) \times (\text{Ways from B to A}) = 10 \times 10 = 100. \]

5. **Conclusion**:
Therefore, the total number of ways a person can travel from A to B and come back is 100.

### Final Answer:
The total number of ways to travel from A to B and come back is **100**.