We know that there are 350 trees in the park.
x% of these trees are pine trees, which means there are (x/100) * 350 pine trees.
The number of trees that are not pine trees is the difference between the total number of trees and the number of pine trees: 350 - (x/100) * 350.
We are given that the number of trees that are not pine trees is 105, so we can write: 350 - (x/100) * 350 = 105.
Simplifying the left side, we get: 350 - 3.5x = 105.
Subtracting 350 from both sides, we get: -3.5x = -245.
Dividing both sides by -3.5, we get: x = 70.
The value of x is 70.
#### 70
The answer is: 70
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
There are 350 trees in the park, x% of which are pine trees. How many are not pine trees?
If we know the answer to the above question is 105, what is the value of unknown variable x?

### Answer:
