In a school, students decided to plant 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 double of the class in which they are studying. If there are 1 to 12 classes in the school and each class has two sections, find how many trees were planted by students. Which value is shown in the question?
Number of trees planted by one section of class 1st = 2
Now, there are 2 sections, ∴ Number of trees planted by class 1st = 4
Number of trees planted by one section of class 2nd = 4
Now, there are 2 sections, ∴ Number of trees planted by class 2nd = 8
This will follow up to class 12th and we will obtain an AP as
4, 8, 12, … upto 12 terms.
Now, Total number of trees planted by the students = 4 + 8 + 12 + … upto 12 terms.
∴ In this Arithmetic series, first term = a = 4
Common difference = d = 4
Now, S12 = (12/2)[2a + (12 - 1)d]
= 6[2(4) + 11(4)]
= 6 × [8 + 44]
= 6 × 52
= 312
∴ Total number of trees planted by the students = 312
Values shown in the question are care and awareness about conservation of nature and environment.