Question

The ${11}^{th}$ term of the series $-5,\frac{-5}{2},0,\frac{5}{2},\cdots$ is

• A. $20$
• B. $30$
• C. $40$
• D. $50$

Answer 1

The correct option is A $20$

$a=-5,d=\frac{5}{2}$ and $n=11$.
$a_{11}=-5+(11-1)\times d$
$a_{11}=-5+10\times \frac{5}{2}$
$a_{11}=20$