Question

Q.6

Answer 1

Since each section of each dass plants five times the number of drees as the dass number and there are three section of each class, we have total number of trees planted by the students from class 1 to 10 

`= 3[1xx5+2xx5+3xx5+......................+10xx5]`

`=3[5+10+15+...........+50]`

`=3[10/2(2xx5xx9xx5)]`

`=3[5(10+45)]`

`=3xx5xx55`

`=825`

Hence,825 trees were planted by  students.