Question

fin the sum of the arithmetic series 3+5+7...+227

Answer 1

can you find the common difference of this arithmetic series ?
or know what common difference is ?

Answer 2

no ?
do you see any pattern in the terms of that series ?

Answer 3

common difference is 2 and the last term is given so you can find number of terms(n) using the formula \[a_{n} = a _{1} + (n-1) \times d\] (where your a1 is 3, an is 227 and d is 2. Then again use \[S _{n} = \frac{ n (a _{1} + a _{n} ) }{ 2 }\] to find your sum Sn.