Question

find this ans of sloution
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Answer 1

Answer:

234

Step-by-step explanation:

AP: 1,2,3.......12

a=1

d=2-1

=1

Sn=n/2[2a+(n-1)d]

S12= 12/2 [2(1)+(12-1) 1]

= 6(2+11)

= 6(13)

=78

therefore no. of trees planted by 1 sec of the class is 78.

No. of trees planted by 3 section of the classes is

3*78= 234

I hope it will help you