Write the first three terms of the $APs$ when $a$ and $d$ are as given below:
$a = -5, d = -3$

Let $S_n$,$S_{2n}$,and $S_{3n}$ be the sums of $n$,$2n$,and $3n$ terms of an Arithmetic Progression $(AP)$,respectively. Prove that $S_{3n} = 3(S_{2n} - S_n)$.

The $21^{\text{st}}$ term of the $AP$ whose first two terms are $-3$ and $4$ is

If $a=2$ and $d=4,$ then $S_{40}=\ldots \ldots \ldots$

The $n^{th}$ term of an $A.P.$ is given by $T_n = 4n + 3$. Find the sum of the first $60$ terms of the $A.P.$

The sum of the first five terms of an $AP$ and the sum of the first seven terms of the same $AP$ is $167$. If the sum of the first ten terms of this $AP$ is $235$,find the sum of its first twenty terms.