Please solve the programming task below using a self-contained code snippet in a markdown code block.

Given a positive integer n, find the sum of all integers in the range [1, n] inclusive that are divisible by 3, 5, or 7.
Return an integer denoting the sum of all numbers in the given range satisfying the constraint.
 
Please complete the following python code precisely:
```python
class Solution:
    def sumOfMultiples(self, n: int) -> int:
```