In a school students thought of planting trees in and around the school to reduce air pollution. It was decided that the number of trees, that each section of each class will plant, will be the same as the class, in which they are studying, e.g., a section of Class I will plant 1 tree, a section of Class II will plant 2 trees and so on till Class XII. There are three sections of each class. How many trees will be planted by the students?

Explanation

To solve the problem of how many trees will be planted by the students, we can break it down into a series of steps:

### Step-by-Step Solution:

1. **Identify the number of classes and sections**:
- There are 12 classes (Class I to Class XII).
- Each class has 3 sections.

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