In an $AP$,if $a = 3.5, d = 0, n = 101$,then $a_{n}$ will be

Which of the following form an $AP$? Justify your answer.
$(i)$ $11, 22, 33, \ldots$
$(ii)$ $\frac{1}{2}, \frac{1}{3}, \frac{1}{4}, \ldots$
$(iii)$ $2, 2^2, 2^3, 2^4, \ldots$
$(iv)$ $\sqrt{3}, \sqrt{12}, \sqrt{27}, \sqrt{48}, \ldots$

For a given $A.P.$,the $5^{th}$ term is $30$ and the $12^{th}$ term is $65$. Find the sum of first $30$ terms of this $A.P.$

Find the sum of the series: $3 + 7 + 11 + \ldots + 119$.

For the $A.P.$ $0.1, 0.4, 0.7, 1, \ldots,$ the common difference is.........

Write the first three terms of the $APs$ when $a$ and $d$ are as given below:
$a=\sqrt{2}, d=\frac{1}{\sqrt{2}}$