For a given $A.P.$,$S_{10} = 50$ and $a = 0.5$. Then,$d = \ldots \ldots \ldots . .$

The $\ldots \ldots \ldots \ldots$th term of the $A.P.$ $8, 11, 14, 17, \ldots$ is $272$.

For any $A.P.$,$T_{25} - T_{20} = \ldots \ldots \ldots$

Which of the following sequences is an $A.P.$?

Kanika was given her pocket money on Jan $1^{\text{st}}, 2008$. She puts $Rs.\, 1$ on Day $1$,$Rs.\, 2$ on Day $2$,$Rs.\, 3$ on Day $3$,and continued doing so till the end of the month,from this money into her piggy bank. She also spent $Rs.\, 204$ of her pocket money,and found that at the end of the month she still had $Rs.\, 100$ with her. How much was her pocket money for the month? (in $Rs.$)

The angles of a triangle are in $AP$. The greatest angle is twice the least. Find all the angles of the triangle (in $^circ$).