Question

The class is asked to plant saplings all along the boundary of their school playground. The are to be planted 40 cm apart. How many saplings would be required given the playground is 60 m long and 20 m wide




*I need full solution no need to send direct answer*​

Answer 1

Answer:

312

Step-by-step explanation:

According to the question , there are two sections of each class so the number of trees that are planted by students of class I, class II, class III, …..& class XII are:

Number of trees planted by the students of two sections of class  I=2×2=4

Number of trees planted by the students of two sections of class II=2×4=8

Similarly,

Number of trees planted by the students of two sections of class 3=2×6=12

Number of trees planted by the students of two sections of class12=2×24=48

So, the number of trees planted by the students of two sections of different classes are4,8,12,……48

This series forms an AP

Here,first term(a)=4, common Difference (d)=8–4=4, last term (l)=48 and (number of terms)n=12

Number of trees planted by the students =sum of 12 terms of above AP

Sn  = n/2[a+1],

Sn = 12/2[4+48],

Sn =6×52=312,

Hence, the total number of trees planted by the students is 312.