For the reaction `AtoB`, the rate of reaction becomes three times when the concentration of A is increased by nine times. What is the order of reaction ?

Explanation

To determine the order of the reaction \( A \to B \), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Rate Law**:
The rate of reaction can be expressed using the rate law:
\[
\text{Rate} = k [A]^n
...