The fourth composite number in the $A.P.$ $5, 7, 9, 11, \ldots$ is......

Match the $APs$ given in column $A$ with suitable common differences given in column $B$.

Column $A$	Column $B$
$(A_{1}) \quad 2, -2, -6, -10, \ldots$	$(B_{1}) \quad \frac{2}{3}$
$(A_{2}) \quad a = -18, n = 10, a_{n} = 0$	$(B_{2}) \quad -5$
$(A_{3}) \quad a = 0, a_{10} = 6$	$(B_{3}) \quad 4$
$(A_{4}) \quad a_{2} = 13, a_{4} = 3$	$(B_{4}) \quad -4$
	$(B_{5}) \quad 2$
	$(B_{6}) \quad \frac{1}{2}$
	$(B_{7}) \quad 5$

The $n^{th}$ term of an $A.P.$ is given by $T_{n} = 10 - 6n$. Find the sum of the first $n$ terms of the $A.P.$

For an $A.P.$,the sum of the $4^{th}$ term and the $8^{th}$ term is $24$,while the sum of the $6^{th}$ term and the $10^{th}$ term is $34$. Find the first term $a$ and the common difference $d$ of the $A.P.$

The $20^{th}$ term of an $A.P.$ is $40$ and the common difference is $2$. Then,its second term is $\ldots \ldots \ldots \ldots$

The $10^{th}$ and $20^{th}$ terms of an $A.P.$ are $73$ and $143$ respectively. Find the first term,the common difference,and the $30^{th}$ term of the $A.P.$