Find the sum given below: $-5 + (-8) + (-11) + \ldots + (-230)$

$a, 2a, 3a, 4a, \dots$ are $APs$? If they form an $AP,$ find the common difference $d$ and write three more terms.

Determine the $AP$ whose third term is $16$ and the $7^{th}$ term exceeds the $5^{th}$ term by $12$.

$A$ manufacturer of $TV$ sets produced $600$ sets in the third year and $700$ sets in the seventh year. Assuming that the production increases uniformly by a fixed number every year,find the total production in first $7$ years.

$200$ logs are stacked in the following manner: $20$ logs in the bottom row,$19$ in the next row,$18$ in the row next to it and so on (see Figure). In how many rows are the $200$ logs placed and how many logs are in the top row?

$A$ manufacturer of $TV$ sets produced $600$ sets in the third year and $700$ sets in the seventh year. Assuming that the production increases uniformly by a fixed number every year,find the production in the $10^{th}$ year.