Question

Find the sum of all the 11 terms of finite A.P whose
middle most term is 30​

Answer 1

Answer:

Given middle term or the sixth term is 30 

As we know, an=a+(n−1)d, where a & d are the first term and common difference of an AP respectively.

Then, a+5d=30

Sum = 2n(2a+(n−1)d)

=211(2a+10d)

Substituting,

=211(2×30)

=330