Question

find the sum of the all 11 terms of an AP whose middle most term is 30

Answer 1

middle term -
$\frac{n + 1}{2} \\ \frac{12}{2} \\ 6$
$t6 = a + 5d \\ a + 5d = 30 \\ s11 = \frac{11}{2} (2a + (11 - 1)d) \\ \frac{11}{2} (2a + 10) \\ \frac{11}{2} \times 2(a + 5d) \\ 11 \times 30 \\ 330$
therefore the sum of all eleven terms is 330.
hope this helps you.
don't forget to do it brainleist.

Answer 2

sum of odd number of terms = middle term ×odd no. of terms

I.e. sum=30×11

=330