Question

find the sum of the series 3+ 9+11+ .......... to 10 times​

Answer 1

Answer:

By the way this is no series.... as common difference is not same.. I am considering this is a series of odd numbers....(3,5,7,9....)

120

Step-by-step explanation:

Here,

a = 3

d = 5-3 = 2

n = 10

Sum of an ap =

$\frac{n}{2} \times (2a + (n - 1)d)$

$= \frac{10}{2} \times (6 + 9(2)) \\ = 5 \times (6 + 18) \\ = 5 \times 24 \\ = 120$

Hope it helps....

Any doubts please comment