Question

Find the sum of the following series. 14 n=1 (2n+1)

A. 448
B. 256
C. 240
D. 224

Answer 1

D. 224

Step-by-step explanation

The given series is

`\sum_(n=1)^(14)(2n+1)`

The first term of this series is

`a_1=2(1) + 1 = 3`

The last term of this series is:

`l = 2(14) + 1 = 29`

The sum of the first n-terms of the series is calculated using the formula,

`S_n= (n)/(2) (a + l)`

`S_ {14}= (14)/(2) (3+ 29)`

`S_ {14}= 7 * (32)`

`S_ {14}= 224`