Question

Find the sum of 11 terms whose middle term is 30

Answer 1

Answer:

330

Step-by-step explanation:

there are 11 terms of AP

the middle term will be the 6th term

a6 = a + 5d = 30

S11

$= \frac{11}{2} (2a + (11 - 1)d) \\ = \frac{11}{2} (2a + 10d) \\ = \frac{11}{2} \times 2(a + 5d) \\ = 11 \times (a + 5d) \\ = 11 \times 30 \: \: \: (since \: a + 5d = 30) \\ = 330$

sum of 11 terms is 330

hope you get your answer