In an $AP$,given $a=8, a_{n}=62, S_{n}=210$,find $n$ and $d$.

For the following $APs$,$-5, -1, 3, 7, \ldots$,write the first term and the common difference.

In an $AP$ given $a_{12}=37$ and $d=3$,find the first term $a$ and the sum of the first $12$ terms $S_{12}$.

For the following $APs$,write the first term and the common difference: $\frac{1}{3}, \frac{5}{3}, \frac{9}{3}, \frac{13}{3}, \ldots$

The sum of the $4^{th}$ and $8^{th}$ terms of an $AP$ is $24$ and the sum of the $6^{th}$ and $10^{th}$ terms is $44$. Find the first three terms of the $AP$.

How many terms of the $AP : 9, 17, 25, \ldots$ must be taken to give a sum of $636$?