If the sum of it terms of an A.P. is 2n<sup>2</sup> + 5n, then its nth term is

If the first, second and last term of an A.P. are a, b and 2a respectively, its sum is

Sum of n terms of the series $$\sqrt 2 $$  $$ + $$  $$\sqrt 8 $$  $$ + $$  $$\sqrt {…

The sum of first n odd natural numbers in

The sum of first five multiples of 3 is:

The common difference of the A.P. is $$\frac{1}{{2q}},$$ $$\frac{{1 - 2q}}{{2q}},$$  $$\frac{{1 - 4q}}{{2q}},$$…

The common difference of the A.P. $$\frac{1}{{2b}},$$ $$\frac{{1 - 6b}}{{2b}},$$  $$\frac{{1 - 12b}}{{2b}},$$ &…

15<sup>th</sup> term of A.P., x - 7, x - 2, x + 3, ........ is