The sum of third and ninth term of an A.P is 8. Find the sum of the first 11 terms of the progression.

A boy agrees to work at the rate of one rupee on the first day, two rupees on the second day, and four rupees on third d…

If 18<sup>th</sup> and 11<sup>th</sup> term of an A.P. are in the ratio 3 : 2, then its 21<su…

Let S denotes the sum of n terms of an A.P. whose first term is a. If the common difference d is given by d = S<sub&g…

The 3<sup>rd</sup> and 9<sup>th</sup> term of an arithmetic progression are -8 and 10 respective…

If the sum of n terms of an A.P. is 3n<sup>2</sup> + 5n then which of its terms is 164 ?

Find the n<sup>th</sup> term of the following sequence :</br> 5 + 55 + 555 + . . . . T<sub>n<…

The n<sup>th</sup> term of an A.P., the sum of whose n terms is S<sub>n</sub>, is