ANSWER
D. 224
EXPLANATION
The given series is
[tex]\sum_{n=1}^{14}(2n+1)[/tex]
The first term of this series is
[tex]a_1=2(1) + 1 = 3[/tex]
The last term of this series is:
[tex]l = 2(14) + 1 = 29[/tex]
The sum of the first n-terms of the series is calculated using the formula,
[tex]S_n= \frac{n}{2} (a + l)[/tex]
[tex]S_ {14}= \frac{14}{2} (3+ 29)[/tex]
[tex]S_ {14}= 7 \times (32)[/tex]
[tex]S_ {14}= 224[/tex]
