Arithmetic Prog...

For an A.P. $$a = -18.9, d = 2.5 \ ,a_n = 3.6,$$ find $$n$$.

Check whether $$-150$$ is a term of the AP:
$$11, 8, 5, 2,...$$

In AP 
Given a =2, d = 8, S$$_n$$ = 90, find n and a$$_n$$

Find the $$20th$$ term from the last term of the AP $$3,8, 13,....253.$$

Which term of the sequence $$ 3, 8, 13, 18, ........$$ is $$498$$.

The $$16th$$ term of the AP: $$15,$$ $$\displaystyle \frac{25}{2},10,\frac{15}{2},........$$ is

If $$\displaystyle \frac{6}{5},$$ $$a,4$$ are in AP, the value of $$a$$ is 

Is $$51$$ a term of the AP, $$5, 8, 11, 14,........?$$

The $$31st$$ term of the AP whose first two terms are respectively $$-2$$ and $$-7$$ is 

The $$11th$$ term of AP whose $$3rd$$ term is $$11$$ and $$8th$$ term is $$26$$ is